Professor Brandeau is the Coleman F. Fung Professor in the School of Engineering and a Professor of Medicine (by Courtesy). Her research focuses on the development of applied mathematical and economic models to support health policy decisions. Her recent work has focused on HIV prevention and treatment programs, programs to control the spread of hepatitis B virus, and public health preparedness plans. She has served as Principal Investigator or Co-PI on a broad range of funded research projects.
She is a Fellow of the Institute for Operations Research and Management Science (INFORMS) and a member of the Omega Rho International Honor Society for Operations Research and Management Science. From INFORMS she has received the President’s Award (recognizing important contributions to the welfare of society), the Pierskalla Prize (for research excellence in health care management science), the Philip McCord Morse Lectureship Award, and the Award for the Advancement of Women in Operations Research and the Management Sciences. She has also received the Award for Excellence in Application of Pharmacoeconomics and Health Outcomes Research from the International Society for Pharmacoeconomics and Outcomes Research, and a Presidential Young Investigator Award from the National Science Foundation, among other awards. Professor Brandeau earned a BS in Mathematics and an MS in Operations Research from MIT, and a PhD in Engineering-Economic Systems from Stanford.
Honors & Awards
Member, Omega Rho Honor Society for Operations Research and Management Science (2015)
Omega Rho Distinguished Lecture on Operations Research and Management Science, Institute for Operations Research and Management Science (2015)
Philip McCord Morse Lecturership Award, Institute for Operations Research and Management Science (2015)
Award for the Advancement of Women in Operations Research and the Management Sciences, Institute for Operations Research and Management Science (2015)
Fellow, INFORMS (Institute for Operations Research and Management Science) (2009)
Graduate Teaching Award, Department of Management Science and Engineering (2008-2009)
Award for Excellence in Application of Pharmacoeconomics and Health Outcomes Research, International Society for Pharmacoeconomics and Outcomes Research (ISPOR) (2008)
President's Award, Institute for Operations Research and Management Science (2008)
Pierskalla Prize, Institute for Operations Research and Management Science (2001)
Annual Outstanding Paper Award, Society for Computer Simulation (1996)
Eugene L. Grant Teaching Award, Stanford School of Engineering (1990-1991)
PYI (Presidential Young Investigator) Award, National Science Foundation (1988-1993)
Boards, Advisory Committees, Professional Organizations
Member, Board of Scientific Counselors, Federal Advisory Committee to CDC Office of Public Health Preparedness & Response (2012 - Present)
Editorial Board Member, Health Care Management Science (1997 - Present)
Member, Institute of Medicine Standing Committee for the CDC Division of the Strategic National Stockpile (2015 - Present)
Member, BSC/NBSB Working Group, Strategic National Stockpile (SNS) Review 20/20 (2012 - 2013)
Member, Institute of Medicine Committee on Prepositioned Medical Countermeasures (2011 - 2011)
Member, Institute of Medicine Committee on the Prevention and Control of Viral Hepatitis Infections in the US (2008 - 2009)
PhD, Stanford University, Engineering-Economic Systems (1985)
MS, Massachusetts Institute of Technology, Operations Research (1978)
BS, Massachusetts Institute of Technology, Mathematics (1977)
Corey A. Billington, Margaret L. Brandeau. "United States Patent 5,258,915 System and Method for Optimum Operation Assignments in Printed Circuit Board Manufacturing", Hewlett-Packard, Nov 2, 1993
- Doctoral Research Seminar in Health Systems Modeling
MS&E 390 (Aut, Win, Spr)
- Health Policy Modeling
MS&E 292 (Win)
Independent Studies (6)
- Biomedical Informatics Teaching Methods
BIOMEDIN 290 (Aut, Win, Spr, Sum)
- Directed Reading and Research
BIOMEDIN 299 (Aut, Win, Spr, Sum)
- Directed Reading and Research
MS&E 408 (Aut, Win, Spr, Sum)
- Medical Scholars Research
BIOMEDIN 370 (Aut, Win, Spr, Sum)
- Ph.D. Qualifying Tutorial or Paper
MS&E 300 (Aut, Win, Spr, Sum)
- Undergraduate Directed Study
MS&E 101 (Aut, Win, Spr, Sum)
- Biomedical Informatics Teaching Methods
Prior Year Courses
- Doctoral Research Seminar in Health Systems Modeling
MS&E 390 (Aut, Spr)
- HIV Policy Issues and Models
OSPCPTWN 56 (Win)
- Health Operations and Policy: Thought Leaders Seminar
MS&E 490 (Aut)
- Healthcare Operations Management
MS&E 263 (Aut)
- Doctoral Research Seminar in Health Systems Modeling
MS&E 390 (Aut, Spr)
- Health Policy Modeling
MS&E 292 (Win)
- Healthcare Operations Management
MS&E 263 (Win)
- Doctoral Research Seminar in Health Systems Modeling
MS&E 390 (Aut, Win, Spr)
- Health Policy Modeling
MS&E 292 (Win)
- Senior Project
MS&E 108 (Win)
- Doctoral Research Seminar in Health Systems Modeling
Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections
2016; 273: 102-113
Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.
View details for DOI 10.1016/j.mbs.2016.01.003
View details for Web of Science ID 000370908500009
View details for PubMedID 26775738
HIV Treatment and Prevention: A Simple Model to Determine Optimal Investment
MEDICAL DECISION MAKING
2016; 36 (3): 391-409
To create a simple model to help public health decision makers determine how to best invest limited resources in HIV treatment scale-up and prevention.A linear model was developed for determining the optimal mix of investment in HIV treatment and prevention, given a fixed budget. The model incorporates estimates of secondary health benefits accruing from HIV treatment and prevention and allows for diseconomies of scale in program costs and subadditive benefits from concurrent program implementation. Data sources were published literature. The target population was individuals infected with HIV or at risk of acquiring it. Illustrative examples of interventions include preexposure prophylaxis (PrEP), community-based education (CBE), and antiretroviral therapy (ART) for men who have sex with men (MSM) in the US. Outcome measures were incremental cost, quality-adjusted life-years gained, and HIV infections averted.Base case analysis indicated that it is optimal to invest in ART before PrEP and to invest in CBE before scaling up ART. Diseconomies of scale reduced the optimal investment level. Subadditivity of benefits did not affect the optimal allocation for relatively low implementation levels. The sensitivity analysis indicated that investment in ART before PrEP was optimal in all scenarios tested. Investment in ART before CBE became optimal when CBE reduced risky behavior by 4% or less. Limitations of the study are that dynamic effects are approximated with a static model.Our model provides a simple yet accurate means of determining optimal investment in HIV prevention and treatment. For MSM in the US, HIV control funds should be prioritized on inexpensive, effective programs like CBE, then on ART scale-up, with only minimal investment in PrEP.
View details for DOI 10.1177/0272989X15598528
View details for Web of Science ID 000371697100011
View details for PubMedID 26369347
Expansion of the National Salt Reduction Initiative: A Mathematical Model of Benefits and Risks of Population-Level Sodium Reduction
MEDICAL DECISION MAKING
2016; 36 (1): 72-85
. The National Salt Reduction Initiative, in which food producers agree to lower sodium to levels deemed feasible for different foods, is expected to significantly reduce sodium intake if expanded to a large sector of food manufacturers.. Given recent data on the relationship between sodium intake, hypertension, and associated cardiovascular disease at a population level, we sought to examine risks and benefits of the program.. To estimate the impact of further expanding the initiative on hypertension, myocardial infarction (MI) and stroke incidence, and related mortality, given food consumption patterns across the United States, we developed and validated a stochastic microsimulation model of hypertension, MI, and stroke morbidity and mortality, using data from food producers on sodium reduction among foods, linked to 24-hour dietary recalls, blood pressure, and cardiovascular histories from the National Health and Nutrition Examination Survey.. Expansion of the initiative to ensure all restaurants and manufacturers reach agreed-upon sodium targets would be expected to avert from 0.9 to 3.0 MIs (a 1.6%-5.4% reduction) and 0.5 to 2.8 strokes (a 1.1%-6.2% reduction) per 10,000 Americans per year over the next decade, after incorporating consumption patterns and variations in the effect of sodium reduction on blood pressure among different demographic groups. Even high levels of consumer addition of table salt or substitution among food categories would be unlikely to neutralize this benefit. However, if recent epidemiological associations between very low sodium and increased mortality are causal, then older women may be at risk of increased mortality from excessively low sodium intake.An expanded National Salt Reduction Initiative is likely to significantly reduce hypertension and hypertension-related cardiovascular morbidity but may be accompanied by potential risks to older women.
View details for DOI 10.1177/0272989X15583846
View details for Web of Science ID 000366910300008
View details for PubMedID 25926284
Evaluating Cost-effectiveness of Interventions That Affect Fertility and Childbearing: How Health Effects Are Measured Matters
MEDICAL DECISION MAKING
2015; 35 (7): 818-846
Current guidelines for economic evaluations of health interventions define relevant outcomes as those accruing to individuals receiving interventions. Little consensus exists on counting health impacts on current and future fertility and childbearing. Our objective was to characterize current practices for counting such health outcomes.We developed a framework characterizing health interventions with direct and/or indirect effects on fertility and childbearing and how such outcomes are reported. We identified interventions spanning the framework and performed a targeted literature review for economic evaluations of these interventions. For each article, we characterized how the potential health outcomes from each intervention were considered, focusing on quality-adjusted life-years (QALYs) associated with fertility and childbearing.We reviewed 108 studies, identifying 7 themes: 1) Studies were heterogeneous in reporting outcomes. 2) Studies often selected outcomes for inclusion that tend to bias toward finding the intervention to be cost-effective. 3) Studies often avoided the challenges of assigning QALYs for pregnancy and fertility by instead considering cost per intermediate outcome. 4) Even for the same intervention, studies took heterogeneous approaches to outcome evaluation. 5) Studies used multiple, competing rationales for whether and how to include fertility-related QALYs and whose QALYs to include. 6) Studies examining interventions with indirect effects on fertility typically ignored such QALYs. 7) Even recent studies had these shortcomings. Limitations include that the review was targeted rather than systematic.Economic evaluations inconsistently consider QALYs from current and future fertility and childbearing in ways that frequently appear biased toward the interventions considered. As the Panel on Cost-Effectiveness in Health and Medicine updates its guidelines, making the practice of cost-effectiveness analysis more consistent is a priority. Our study contributes to harmonizing methods in this respect.
View details for DOI 10.1177/0272989X15583845
View details for Web of Science ID 000361570600005
View details for PubMedID 25926281
Link removal for the control of stochastically evolving epidemics over networks: A comparison of approaches
JOURNAL OF THEORETICAL BIOLOGY
2015; 371: 154-165
For many communicable diseases, knowledge of the underlying contact network through which the disease spreads is essential to determining appropriate control measures. When behavior change is the primary intervention for disease prevention, it is important to understand how to best modify network connectivity using the limited resources available to control disease spread. We describe and compare four algorithms for selecting a limited number of links to remove from a network: two "preventive" approaches (edge centrality, R0 minimization), where the decision of which links to remove is made prior to any disease outbreak and depends only on the network structure; and two "reactive" approaches (S-I edge centrality, optimal quarantining), where information about the initial disease states of the nodes is incorporated into the decision of which links to remove. We evaluate the performance of these algorithms in minimizing the total number of infections that occur over the course of an acute outbreak of disease. We consider different network structures, including both static and dynamic Erdös-Rényi random networks with varying levels of connectivity, a real-world network of residential hotels connected through injection drug use, and a network exhibiting community structure. We show that reactive approaches outperform preventive approaches in averting infections. Among reactive approaches, removing links in order of S-I edge centrality is favored when the link removal budget is small, while optimal quarantining performs best when the link removal budget is sufficiently large. The budget threshold above which optimal quarantining outperforms the S-I edge centrality algorithm is a function of both network structure (higher for unstructured Erdös-Rényi random networks compared to networks with community structure or the real-world network) and disease infectiousness (lower for highly infectious diseases). We conduct a value-of-information analysis of knowing which nodes are initially infected by comparing the performance improvement achieved by reactive over preventive strategies. We find that such information is most valuable for moderate budget levels, with increasing value as disease spread becomes more likely (due to either increased connectedness of the network or increased infectiousness of the disease).
View details for DOI 10.1016/j.jtbi.2015.02.005
View details for Web of Science ID 000353011200014
View details for PubMedID 25698229
Modeling and Calibration for Exposure to Time-Varying, Modifiable Risk Factors: The Example of Smoking Behavior in India
MEDICAL DECISION MAKING
2015; 35 (2): 196-210
Risk factors increase the incidence and severity of chronic disease. To examine future trends and develop policies addressing chronic diseases, it is important to capture the relationship between exposure and disease development, which is challenging given limited data.To develop parsimonious risk factor models embeddable in chronic disease models, which are useful when longitudinal data are unavailable.The model structures encode relevant features of risk factors (e.g., time-varying, modifiable) and can be embedded in chronic disease models. Calibration captures time-varying exposures for the risk factor models using available cross-sectional data. We illustrate feasibility with the policy-relevant example of smoking in India.The model is calibrated to the prevalence of male smoking in 12 Indian regions estimated from the 2009-2010 Indian Global Adult Tobacco Survey. Nelder-Mead searches (250,000 starting locations) identify distributions of starting, quitting, and restarting rates that minimize the difference between modeled and observed age-specific prevalence. We compare modeled life expectancies to estimates in the absence of time-varying risk exposures and consider gains from hypothetical smoking cessation programs delivered for 1 to 30 years.Calibration achieves concordance between modeled and observed outcomes. Probabilities of starting to smoke rise and fall with age, while quitting and restarting probabilities fall with age. Accounting for time-varying smoking exposures is important, as not doing so produces smaller estimates of life expectancy losses. Estimated impacts of smoking cessation programs delivered for different periods depend on the fact that people who have been induced to abstain from smoking longer are less likely to restart.The approach described is feasible for important risk factors for numerous chronic diseases. Incorporating exposure-change rates can improve modeled estimates of chronic disease outcomes and of the long-term effects of interventions targeting risk factors.
View details for DOI 10.1177/0272989X13518272
View details for Web of Science ID 000348054300010
View details for PubMedID 24477078
Creating impact with operations research in health: making room for practice in academia.
Health care management science
Operations research (OR)-based analyses have the potential to improve decision making for many important, real-world health care problems. However, junior scholars often avoid working on practical applications in health because promotion and tenure processes tend to value theoretical studies more highly than applied studies. This paper discusses the author's experiences in using OR to inform and influence decisions in health and provides a blueprint for junior researchers who wish to find success by taking a similar path. This involves selecting good problems to study, forming productive collaborations with domain experts, developing appropriate models, identifying the most salient results from an analysis, and effectively disseminating findings to decision makers. The paper then suggests how journals, funding agencies, and senior academics can encourage such work by taking a broader and more informed view of the potential role and contributions of OR to solving health care problems. Making room in academia for the application of OR in health follows in the tradition begun by the founders of operations research: to work on important real-world problems where operations research can contribute to better decision making.
View details for DOI 10.1007/s10729-015-9328-0
View details for PubMedID 26003321
Optimizing patient treatment decisions in an era of rapid technological advances: the case of hepatitis C treatment.
Health care management science
How long should a patient with a treatable chronic disease wait for more effective treatments before accepting the best available treatment? We develop a framework to guide optimal treatment decisions for a deteriorating chronic disease when treatment technologies are improving over time. We formulate an optimal stopping problem using a discrete-time, finite-horizon Markov decision process. The goal is to maximize a patient's quality-adjusted life expectancy. We derive structural properties of the model and analytically solve a three-period treatment decision problem. We illustrate the model with the example of treatment for chronic hepatitis C virus (HCV). Chronic HCV affects 3-4 million Americans and has been historically difficult to treat, but increasingly effective treatments have been commercialized in the past few years. We show that the optimal treatment decision is more likely to be to accept currently available treatment-despite expectations for future treatment improvement-for patients who have high-risk history, who are older, or who have more comorbidities. Insights from this study can guide HCV treatment decisions for individual patients. More broadly, our model can guide treatment decisions for curable chronic diseases by finding the optimal treatment policy for individual patients in a heterogeneous population.
View details for DOI 10.1007/s10729-015-9330-6
View details for PubMedID 26188961
HIV epidemic control-a model for optimal allocation of prevention and treatment resources
HEALTH CARE MANAGEMENT SCIENCE
2014; 17 (2): 162-181
With 33 million people living with human immunodeficiency virus (HIV) worldwide and 2.7 million new infections occurring annually, additional HIV prevention and treatment efforts are urgently needed. However, available resources for HIV control are limited and must be used efficiently to minimize the future spread of the epidemic. We develop a model to determine the appropriate resource allocation between expanded HIV prevention and treatment services. We create an epidemic model that incorporates multiple key populations with different transmission modes, as well as production functions that relate investment in prevention and treatment programs to changes in transmission and treatment rates. The goal is to allocate resources to minimize R 0, the reproductive rate of infection. We first develop a single-population model and determine the optimal resource allocation between HIV prevention and treatment. We extend the analysis to multiple independent populations, with resource allocation among interventions and populations. We then include the effects of HIV transmission between key populations. We apply our model to examine HIV epidemic control in two different settings, Uganda and Russia. As part of these applications, we develop a novel approach for estimating empirical HIV program production functions. Our study provides insights into the important question of resource allocation for a country's optimal response to its HIV epidemic and provides a practical approach for decision makers. Better decisions about allocating limited HIV resources can improve response to the epidemic and increase access to HIV prevention and treatment services for millions of people worldwide.
View details for DOI 10.1007/s10729-013-9240-4
View details for Web of Science ID 000341086500006
View details for PubMedID 23793895
Expanded HIV Testing in Low-Prevalence, High-Income Countries: A Cost-Effectiveness Analysis for the United Kingdom
2014; 9 (4)
In many high-income countries with low HIV prevalence, significant numbers of persons living with HIV (PLHIV) remain undiagnosed. Identification of PLHIV via HIV testing offers timely access to lifesaving antiretroviral therapy (ART) and decreases HIV transmission. We estimated the effectiveness and cost-effectiveness of HIV testing in the United Kingdom (UK), where 25% of PLHIV are estimated to be undiagnosed.We developed a dynamic compartmental model to analyze strategies to expand HIV testing and treatment in the UK, with particular focus on men who have sex with men (MSM), people who inject drugs (PWID), and individuals from HIV-endemic countries.We estimated HIV prevalence, incidence, quality-adjusted life years (QALYs), and health care costs over 10 years, and cost-effectiveness.Annual HIV testing of all adults could avert 5% of new infections, even with no behavior change following HIV diagnosis because of earlier ART initiation, or up to 18% if risky behavior is halved. This strategy costs £67,000-£106,000/QALY gained. Providing annual testing only to MSM, PWID, and people from HIV-endemic countries, and one-time testing for all other adults, prevents 4-15% of infections, requires one-fourth as many tests to diagnose each PLHIV, and costs £17,500/QALY gained. Augmenting this program with increased ART access could add 145,000 QALYs to the population over 10 years, at £26,800/QALY gained.Annual HIV testing of key populations in the UK is very cost-effective. Additional one-time testing of all other adults could identify the majority of undiagnosed PLHIV. These findings are potentially relevant to other low-prevalence, high-income countries.
View details for DOI 10.1371/journal.pone.0095735
View details for Web of Science ID 000335505000031
View details for PubMedID 24763373
Effectiveness and Cost Effectiveness of Oral Pre-Exposure Prophylaxis in a Portfolio of Prevention Programs for Injection Drug Users in Mixed HIV Epidemics
2014; 9 (1)
Pre-exposure prophylaxis with oral antiretroviral treatment (oral PrEP) for HIV-uninfected injection drug users (IDUs) is potentially useful in controlling HIV epidemics with a significant injection drug use component. We estimated the effectiveness and cost effectiveness of strategies for using oral PrEP in various combinations with methadone maintenance treatment (MMT) and antiretroviral treatment (ART) in Ukraine, a representative case for mixed HIV epidemics.We developed a dynamic compartmental model of the HIV epidemic in a population of non-IDUs, IDUs who inject opiates, and IDUs in MMT, adding an oral PrEP program (tenofovir/emtricitabine, 49% susceptibility reduction) for uninfected IDUs. We analyzed intervention portfolios consisting of oral PrEP (25% or 50% of uninfected IDUs), MMT (25% of IDUs), and ART (80% of all eligible patients). We measured health care costs, quality-adjusted life years (QALYs), HIV prevalence, HIV infections averted, and incremental cost effectiveness. A combination of PrEP for 50% of IDUs and MMT lowered HIV prevalence the most in both IDUs and the general population. ART combined with MMT and PrEP (50% access) averted the most infections (14,267). For a PrEP cost of $950, the most cost-effective strategy was MMT, at $520/QALY gained versus no intervention. The next most cost-effective strategy consisted of MMT and ART, costing $1,000/QALY gained compared to MMT alone. Further adding PrEP (25% access) was also cost effective by World Health Organization standards, at $1,700/QALY gained. PrEP alone became as cost effective as MMT at a cost of $650, and cost saving at $370 or less.Oral PrEP for IDUs can be part of an effective and cost-effective strategy to control HIV in regions where injection drug use is a significant driver of the epidemic. Where budgets are limited, focusing on MMT and ART access should be the priority, unless PrEP has low cost.
View details for DOI 10.1371/journal.pone.0086584
View details for Web of Science ID 000330510000062
View details for PubMedID 24489747
Too Much of a Good Thing? When to Stop Catch-Up Vaccination
MEDICAL DECISION MAKING
2013; 33 (7): 920-936
During the 20th century, deaths from a range of serious infectious diseases decreased dramatically due to the development of safe and effective vaccines. However, infant immunization coverage has increased only marginally since the 1960s, and many people remain susceptible to vaccine-preventable diseases. "Catch-up vaccination" for age groups beyond infancy can be an attractive and effective means of immunizing people who were missed earlier. However, as newborn vaccination rates increase, catch-up vaccination becomes less attractive: the number of susceptible people decreases, so the cost to find and vaccinate each unvaccinated person may increase; in addition, the number of infected individuals decreases, so each unvaccinated person faces a lower risk of infection. This article presents a general framework for determining the optimal time to discontinue a catch-up vaccination program. We use a cost-effectiveness framework: we consider the cost per quality-adjusted life year gained of catch-up vaccination efforts as a function of newborn immunization rates over time and consequent disease prevalence and incidence. We illustrate our results with the example of hepatitis B catch-up vaccination in China. We contrast results from a dynamic modeling approach with an approach that ignores the impact of vaccination on future disease incidence. The latter approach is likely to be simpler for decision makers to understand and implement because of lower data requirements.
View details for DOI 10.1177/0272989X13493142
View details for Web of Science ID 000324535200004
View details for PubMedID 23858015
- National Biodefense Science Board/Board of Scientific Counselors Strategic National Stockpile 2020 Joint Working Group. Anticipated Responsibilities of the Strategic National Stockpile (SNS) in the Year 2020 – An Examination with Recommendations. Washington, DC 2013
- Too much of a good thing? When to stop catch-up vaccination. Medical Decision Making 2013; 7 (33): 920-936.
- REACH: A practical HIV resource allocation tool for decision makers. In Operations Research and Health Care Policy edited by Zaric, G., S. Springer Publishers, New York. 2013: 201-224.
- Are organic foods safer or healthier? [Letter]. [Letter]. Annals of Internal Medicine. 2013; 4 (158): 297-300.
- OR in public health: A little help can go a long way. In Operations Research and Health Care Policy edited by Zaric, G., S. Springer Publishers, New York. 2013: 17-38.
- HIV epidemic control: A model for optimal allocation of prevention and treatment resources. Health Care Management Science, Epub ahead of print. 2013
Balancing Immunological Benefits and Cardiovascular Risks of Antiretroviral Therapy: When Is Immediate Treatment Optimal?
CLINICAL INFECTIOUS DISEASES
2012; 55 (10): 1392-1399
We developed a mathematical model to identify the timing of antiretroviral therapy (ART) initiation that optimizes patient outcomes as a function of patient CD4 count, age, cardiac mortality risk, sex, and personal preferences. Our goal was to find the conditions that maximize patient quality-adjusted life expectancy (QALE) in the context of our model. Under the assumption that ART confers disease progression and mortality benefits at any CD4 count, immediate treatment initiation yields the greatest remaining QALE for young patients under most circumstances. The timing of ART initiation depends on the magnitude of benefit from ART at high CD4 counts, the magnitude of increases in cardiac risk, and patients' preferences. If ART reduces HIV progression at high CD4 counts, immediate ART is preferable for most newly infected individuals <35 years even if ART doubles age- and sex-specific cardiac risk.
View details for DOI 10.1093/cid/cis731
View details for Web of Science ID 000310374600023
View details for PubMedID 22942203
Cost Effectiveness of Screening Strategies for Early Identification of HIV and HCV Infection in Injection Drug Users
2012; 7 (9)
To estimate the cost, effectiveness, and cost effectiveness of HIV and HCV screening of injection drug users (IDUs) in opioid replacement therapy (ORT).Dynamic compartmental model of HIV and HCV in a population of IDUs and non-IDUs for a representative U.S. urban center with 2.5 million adults (age 15-59).We considered strategies of screening individuals in ORT for HIV, HCV, or both infections by antibody or antibody and viral RNA testing. We evaluated one-time and repeat screening at intervals from annually to once every 3 months. We calculated the number of HIV and HCV infections, quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs).Adding HIV and HCV viral RNA testing to antibody testing averts 14.8-30.3 HIV and 3.7-7.7 HCV infections in a screened population of 26,100 IDUs entering ORT over 20 years, depending on screening frequency. Screening for HIV antibodies every 6 months costs $30,700/QALY gained. Screening for HIV antibodies and viral RNA every 6 months has an ICER of $65,900/QALY gained. Strategies including HCV testing have ICERs exceeding $100,000/QALY gained unless awareness of HCV-infection status results in a substantial reduction in needle-sharing behavior.Although annual screening for antibodies to HIV and HCV is modestly cost effective compared to no screening, more frequent screening for HIV provides additional benefit at less cost. Screening individuals in ORT every 3-6 months for HIV infection using both antibody and viral RNA technologies and initiating ART for acute HIV infection appears cost effective.
View details for DOI 10.1371/journal.pone.0045176
View details for Web of Science ID 000311313900091
View details for PubMedID 23028828
Are organic foods safer or healthier than conventional alternatives?: a systematic review.
Annals of internal medicine
2012; 157 (5): 348-366
The health benefits of organic foods are unclear.To review evidence comparing the health effects of organic and conventional foods.MEDLINE (January 1966 to May 2011), EMBASE, CAB Direct, Agricola, TOXNET, Cochrane Library (January 1966 to May 2009), and bibliographies of retrieved articles.English-language reports of comparisons of organically and conventionally grown food or of populations consuming these foods.2 independent investigators extracted data on methods, health outcomes, and nutrient and contaminant levels.17 studies in humans and 223 studies of nutrient and contaminant levels in foods met inclusion criteria. Only 3 of the human studies examined clinical outcomes, finding no significant differences between populations by food type for allergic outcomes (eczema, wheeze, atopic sensitization) or symptomatic Campylobacter infection. Two studies reported significantly lower urinary pesticide levels among children consuming organic versus conventional diets, but studies of biomarker and nutrient levels in serum, urine, breast milk, and semen in adults did not identify clinically meaningful differences. All estimates of differences in nutrient and contaminant levels in foods were highly heterogeneous except for the estimate for phosphorus; phosphorus levels were significantly higher than in conventional produce, although this difference is not clinically significant. The risk for contamination with detectable pesticide residues was lower among organic than conventional produce (risk difference, 30% [CI, -37% to -23%]), but differences in risk for exceeding maximum allowed limits were small. Escherichia coli contamination risk did not differ between organic and conventional produce. Bacterial contamination of retail chicken and pork was common but unrelated to farming method. However, the risk for isolating bacteria resistant to 3 or more antibiotics was higher in conventional than in organic chicken and pork (risk difference, 33% [CI, 21% to 45%]).Studies were heterogeneous and limited in number, and publication bias may be present.The published literature lacks strong evidence that organic foods are significantly more nutritious than conventional foods. Consumption of organic foods may reduce exposure to pesticide residues and antibiotic-resistant bacteria.None.
View details for DOI 10.7326/0003-4819-157-5-201209040-00007
View details for PubMedID 22944875
Are Organic Foods Safer or Healthier Than Conventional Alternatives?
ANNALS OF INTERNAL MEDICINE
2012; 157 (5): 348-U112
View details for Web of Science ID 000308361500005
The Cost-Effectiveness of Preexposure Prophylaxis for HIV Prevention in the United States in Men Who Have Sex With Men
ANNALS OF INTERNAL MEDICINE
2012; 156 (8): 541-U144
A recent randomized, controlled trial showed that daily oral preexposure chemoprophylaxis (PrEP) was effective for HIV prevention in men who have sex with men (MSM). The Centers for Disease Control and Prevention recently provided interim guidance for PrEP in MSM at high risk for HIV. Previous studies did not reach a consistent estimate of its cost-effectiveness.To estimate the effectiveness and cost-effectiveness of PrEP in MSM in the United States.Dynamic model of HIV transmission and progression combined with a detailed economic analysis.Published literature.MSM aged 13 to 64 years in the United States.Lifetime.Societal.PrEP was evaluated in both the general MSM population and in high-risk MSM and was assumed to reduce infection risk by 44% on the basis of clinical trial results.New HIV infections, discounted quality-adjusted life-years (QALYs) and costs, and incremental cost-effectiveness ratios.Initiating PrEP in 20% of MSM in the United States would reduce new HIV infections by an estimated 13% and result in a gain of 550,166 QALYs over 20 years at a cost of $172,091 per QALY gained. Initiating PrEP in a larger proportion of MSM would prevent more infections but at an increasing cost per QALY gained (up to $216,480 if all MSM receive PrEP). Preexposure chemoprophylaxis in only high-risk MSM can improve cost-effectiveness. For MSM with an average of 5 partners per year, PrEP costs approximately $50,000 per QALY gained. Providing PrEP to all high-risk MSM for 20 years would cost $75 billion more in health care-related costs than the status quo and $600,000 per HIV infection prevented, compared with incremental costs of $95 billion and $2 million per infection prevented for 20% coverage of all MSM.PrEP in the general MSM population would cost less than $100,000 per QALY gained if the daily cost of antiretroviral drugs for PrEP was less than $15 or if PrEP efficacy was greater than 75%.When examining PrEP in high-risk MSM, the investigators did not model a mix of low- and high-risk MSM because of lack of data on mixing patterns.PrEP in the general MSM population could prevent a substantial number of HIV infections, but it is expensive. Use in high-risk MSM compares favorably with other interventions that are considered cost-effective but could result in annual PrEP expenditures of more than $4 billion.National Institute on Drug Abuse, Department of Veterans Affairs, and National Institute of Allergy and Infectious Diseases.
View details for DOI 10.1059/0003-4819-156-8-201204170-00001
View details for Web of Science ID 000303151800013
View details for PubMedID 22508731
Optimal link removal for epidemic mitigation: A two-way partitioning approach
2012; 235 (2): 138-147
The structure of the contact network through which a disease spreads may influence the optimal use of resources for epidemic control. In this work, we explore how to minimize the spread of infection via quarantining with limited resources. In particular, we examine which links should be removed from the contact network, given a constraint on the number of removable links, such that the number of nodes which are no longer at risk for infection is maximized. We show how this problem can be posed as a non-convex quadratically constrained quadratic program (QCQP), and we use this formulation to derive a link removal algorithm. The performance of our QCQP-based algorithm is validated on small Erd?s-Renyi and small-world random graphs, and then tested on larger, more realistic networks, including a real-world network of injection drug use. We show that our approach achieves near optimal performance and out-performs other intuitive link removal algorithms, such as removing links in order of edge centrality.
View details for DOI 10.1016/j.mbs.2011.11.006
View details for Web of Science ID 000301020300003
View details for PubMedID 22115862
Decision Making for HIV Prevention and Treatment Scale up: Bridging the Gap between Theory and Practice
MEDICAL DECISION MAKING
2012; 32 (1): 105-117
Effectively controlling the HIV epidemic will require efficient use of limited resources. Despite ambitious global goals for HIV prevention and treatment scale up, few comprehensive practical tools exist to inform such decisions.We briefly summarize modeling approaches for resource allocation for epidemic control, and discuss the practical limitations of these models. We describe typical challenges of HIV resource allocation in practice and some of the tools used by decision makers. We identify the characteristics needed in a model that can effectively support planners in decision making about HIV prevention and treatment scale up.An effective model to support HIV scale-up decisions will be flexible, with capability for parameter customization and incorporation of uncertainty. Such a model needs certain key technical features: it must capture epidemic effects; account for how intervention effectiveness depends on the target population and the level of scale up; capture benefit and cost differentials for packages of interventions versus single interventions, including both treatment and prevention interventions; incorporate key constraints on potential funding allocations; identify optimal or near-optimal solutions; and estimate the impact of HIV interventions on the health care system and the resulting resource needs. Additionally, an effective model needs a user-friendly design and structure, ease of calibration and validation, and accessibility to decision makers in all settings.Resource allocation theory can make a significant contribution to decision making about HIV prevention and treatment scale up. What remains now is to develop models that can bridge the gap between theory and practice.
View details for DOI 10.1177/0272989X10391808
View details for Web of Science ID 000299701100014
View details for PubMedID 21191118
Assessing effectiveness and cost-effectiveness of concurrency reduction for HIV prevention
INTERNATIONAL JOURNAL OF STD & AIDS
2011; 22 (10): 558-567
We estimated the effectiveness and cost-effectiveness of changes in concurrent sexual partnerships in reducing the spread of HIV in sub-Saharan Africa. Using data from Swaziland, Tanzania, Uganda and Zambia, we estimated country-specific concurrency behaviour from sexual behaviour survey data on the number of partners in the past 12 months, and we developed a network model to compare the impact of three behaviour changes on the HIV epidemic: (1) changes in concurrent partnership patterns to strict monogamy; (2) partnership reduction among those with the greatest number of partners; and (3) partnership reduction among all individuals. We estimated the number of new HIV infections over 10 years and the cost per infection averted. Given our assumptions and model structure, we find that reducing concurrency among high-risk individuals averts the most infections and increasing monogamy the least (11.7% versus 8.7% reduction in new infections, on average, for a 10% reduction in concurrent partnerships). A campaign that costs US$1 per person annually is likely cost-saving if it reduces concurrency by 9% on average, given our baseline estimates of concurrency. In sensitivity analysis, the rank ordering of behaviour change scenarios was unaffected by potential over-estimation of concurrency, though the number of infections averted decreased and the cost per HIV infection averted increased. Concurrency reduction programmes may be effective and cost-effective in reducing HIV incidence in sub-Saharan Africa if they can achieve even modest impacts at similar costs to past mass media campaigns in the region. Reduced concurrency among high-risk individuals appears to be most effective in reducing HIV incidence, but concurrency reduction in other risk groups may yield nearly as much benefit.
View details for DOI 10.1258/ijsa.2011.010322
View details for Web of Science ID 000296991200004
View details for PubMedID 21998175
The cost-effectiveness of symptom-based testing and routine screening for acute HIV infection in men who have sex with men in the USA
2011; 25 (14): 1779-1787
Acute HIV infection often causes influenza-like illness (ILI) and is associated with high infectivity. We estimated the effectiveness and cost-effectiveness of strategies to identify and treat acute HIV infection in men who have sex with men (MSM) in the USA.Dynamic model of HIV transmission and progression.We evaluated three testing approaches: viral load testing for individuals with ILI, expanded screening with antibody testing, and expanded screening with antibody and viral load testing. We included treatment with antiretroviral therapy for individuals identified as acutely infected.New HIV infections, discounted quality-adjusted life years (QALYs) and costs, and incremental cost-effectiveness ratios.At the present rate of HIV-antibody testing, we estimated that 538,000 new infections will occur among MSM over the next 20 years. Expanding antibody screening coverage to 90% of MSM annually reduces new infections by 2.8% and costs US$ 12,582 per QALY gained. Symptom-based viral load testing with ILI is more expensive than expanded antibody screening, but is more effective and costs US$ 22,786 per QALY gained. Combining expanded antibody screening with symptom-based viral load testing prevents twice as many infections compared to expanded antibody screening alone, and costs US$ 29,923 per QALY gained. Adding viral load testing to all annual HIV tests costs more than US$ 100,000 per QALY gained.Use of HIV viral load testing in MSM with ILI prevents more infections than does expanded annual antibody screening alone and is inexpensive relative to other screening interventions. Clinicians should consider symptom-based viral load testing in MSM, in addition to encouraging annual antibody screening.
View details for DOI 10.1097/QAD.0b013e328349f067
View details for Web of Science ID 000294415200012
View details for PubMedID 21716076
- Efficient stockpiling and shipping policies for humanitarian relief: UNHCR's inventory challenge OR SPECTRUM 2011; 33 (3): 673-698
Inferring model parameters in network-based disease simulation
HEALTH CARE MANAGEMENT SCIENCE
2011; 14 (2): 174-188
Many models of infectious disease ignore the underlying contact structure through which the disease spreads. However, in order to evaluate the efficacy of certain disease control interventions, it may be important to include this network structure. We present a network modeling framework of the spread of disease and a methodology for inferring important model parameters, such as those governing network structure and network dynamics, from readily available data sources. This is a general and flexible framework with wide applicability to modeling the spread of disease through sexual or close contact networks. To illustrate, we apply this modeling framework to evaluate HIV control programs in sub-Saharan Africa, including programs aimed at concurrent partnership reduction, reductions in risky sexual behavior, and scale up of HIV treatment.
View details for DOI 10.1007/s10729-011-9150-2
View details for Web of Science ID 000290039400005
View details for PubMedID 21373984
Doing Good with Good OR: Supporting Cost-Effective Hepatitis B Interventions
2011; 41 (3): 289-300
In an era of limited healthcare budgets, mathematical models can be useful tools to identify cost-effective programs and to support policymakers in informed decision making. This paper reports results of our work carried out over several years with the Asian Liver Center at Stanford University, a nonprofit outreach and advocacy organization that is an international leader in the fight against hepatitis B and liver cancer. Hepatitis B is a vaccine-preventable viral disease that, if untreated, can lead to death from cirrhosis and liver cancer. Infection with hepatitis B is a major public health problem, particularly in Asian populations. We used new combinations of decision analysis and Markov models to analyze the cost-effectiveness of several interventions to combat hepatitis B in the United States and China. The results of our OR-based analyses have helped change United States public health policy on hepatitis B screening for millions of people and have helped encourage policymakers in China to enact legislation to provide free catch-up vaccination for hundreds of millions of children. These policies are an important step in eliminating health disparities, reducing discrimination, and ensuring that millions of people who need it can now receive hepatitis B vaccination or lifesaving treatment.
View details for DOI 10.1287/inte.1100.0511
View details for Web of Science ID 000292246700007
View details for PubMedID 21760650
Effectiveness and Cost Effectiveness of Expanding Harm Reduction and Antiretroviral Therapy in a Mixed HIV Epidemic: A Modeling Analysis for Ukraine
2011; 8 (3)
Injection drug use (IDU) and heterosexual virus transmission both contribute to the growing mixed HIV epidemics in Eastern Europe and Central Asia. In Ukraine-chosen in this study as a representative country-IDU-related risk behaviors cause half of new infections, but few injection drug users (IDUs) receive methadone substitution therapy. Only 10% of eligible individuals receive antiretroviral therapy (ART). The appropriate resource allocation between these programs has not been studied. We estimated the effectiveness and cost-effectiveness of strategies for expanding methadone substitution therapy programs and ART in mixed HIV epidemics, using Ukraine as a case study.We developed a dynamic compartmental model of the HIV epidemic in a population of non-IDUs, IDUs using opiates, and IDUs on methadone substitution therapy, stratified by HIV status, and populated it with data from the Ukraine. We considered interventions expanding methadone substitution therapy, increasing access to ART, or both. We measured health care costs, quality-adjusted life years (QALYs), HIV prevalence, infections averted, and incremental cost-effectiveness. Without incremental interventions, HIV prevalence reached 67.2% (IDUs) and 0.88% (non-IDUs) after 20 years. Offering methadone substitution therapy to 25% of IDUs reduced prevalence most effectively (to 53.1% IDUs, 0.80% non-IDUs), and was most cost-effective, averting 4,700 infections and adding 76,000 QALYs compared with no intervention at US$530/QALY gained. Expanding both ART (80% coverage of those eligible for ART according to WHO criteria) and methadone substitution therapy (25% coverage) was the next most cost-effective strategy, adding 105,000 QALYs at US$1,120/QALY gained versus the methadone substitution therapy-only strategy and averting 8,300 infections versus no intervention. Expanding only ART (80% coverage) added 38,000 QALYs at US$2,240/QALY gained versus the methadone substitution therapy-only strategy, and averted 4,080 infections versus no intervention. Offering ART to 80% of non-IDUs eligible for treatment by WHO criteria, but only 10% of IDUs, averted only 1,800 infections versus no intervention and was not cost effective.Methadone substitution therapy is a highly cost-effective option for the growing mixed HIV epidemic in Ukraine. A strategy that expands both methadone substitution therapy and ART to high levels is the most effective intervention, and is very cost effective by WHO criteria. When expanding ART, access to methadone substitution therapy provides additional benefit in infections averted. Our findings are potentially relevant to other settings with mixed HIV epidemics. Please see later in the article for the Editors' Summary.
View details for DOI 10.1371/journal.pmed.1000423
View details for Web of Science ID 000288945200004
View details for PubMedID 21390264
- Institute of Medicine Committee on Prepositioned Medical Countermeasures. Prepositioning Antibiotics for Anthrax. 2011
- Efficient stockpiling and shipping strategies for humanitarian relief: UNHCR’s inventory challenge. OR Spectrum 2011; 3 (33): 673-698.
- Inferring model parameters in network-based disease simulation. Health Care Management Science 2011; 2 (14): 174-188.
- The cost-effectiveness of symptom-based testing and routine screening for acute HIV infection in men who have sex with men in the United States. AIDS 2011; 14 (25): 1779-1787.
The Cost-Effectiveness and Population Outcomes of Expanded HIV Screening and Antiretroviral Treatment in the United States
ANNALS OF INTERNAL MEDICINE
2010; 153 (12): 778-?
Although recent guidelines call for expanded routine screening for HIV, resources for antiretroviral therapy (ART) are limited, and all eligible persons are not currently receiving treatment.To evaluate the effects on the U.S. HIV epidemic of expanded ART, HIV screening, or interventions to reduce risk behavior.Dynamic mathematical model of HIV transmission and disease progression and cost-effectiveness analysis.Published literature.High-risk (injection drug users and men who have sex with men) and low-risk persons aged 15 to 64 years in the United States.Twenty years and lifetime (costs and quality-adjusted life-years [QALYs]).Societal.Expanded HIV screening and counseling, treatment with ART, or both.New HIV infections, discounted costs and QALYs, and incremental cost-effectiveness ratios.One-time HIV screening of low-risk persons coupled with annual screening of high-risk persons could prevent 6.7% of a projected 1.23 million new infections and cost $22,382 per QALY gained, assuming a 20% reduction in sexual activity after screening. Expanding ART utilization to 75% of eligible persons prevents 10.3% of infections and costs $20,300 per QALY gained. A combination strategy prevents 17.3% of infections and costs $21,580 per QALY gained.With no reduction in sexual activity, expanded screening prevents 3.7% of infections. Earlier ART initiation when a CD4 count is greater than 0.350 × 10(9) cells/L prevents 20% to 28% of infections. Additional efforts to halve high-risk behavior could reduce infections by 65%.The model of disease progression and treatment was simplified, and acute HIV screening was excluded.Expanding HIV screening and treatment simultaneously offers the greatest health benefit and is cost-effective. However, even substantial expansion of HIV screening and treatment programs is not sufficient to markedly reduce the U.S. HIV epidemic without substantial reductions in risk behavior.National Institute on Drug Abuse, National Institutes of Health, and Department of Veterans Affairs.
View details for Web of Science ID 000285453700027
View details for PubMedID 21173412
Cost-Effectiveness of Strategies for Diagnosing Pulmonary Embolism Among Emergency Department Patients Presenting With Undifferentiated Symptoms
ANNALS OF EMERGENCY MEDICINE
2010; 56 (4): 321-332
Symptoms associated with pulmonary embolism can be nonspecific and similar to many competing diagnoses, leading to excessive costly testing and treatment, as well as missed diagnoses. Objective studies are essential for diagnosis. This study evaluates the cost-effectiveness of different diagnostic strategies in an emergency department (ED) for patients presenting with undifferentiated symptoms suggestive of pulmonary embolism.Using a probabilistic decision model, we evaluated the incremental costs and effectiveness (quality-adjusted life-years gained) of 60 testing strategies for 5 patient pretest categories (distinguished by Wells score [high, moderate, or low] and whether deep venous thrombosis is clinically suspected). We performed deterministic and probabilistic sensitivity analyses.In the base case, for all patient pretest categories, the most cost-effective diagnostic strategy is to use an initial enzyme-linked immunosorbent assay D-dimer test, followed by compression ultrasonography of the lower extremities if the D-dimer is above a specified cutoff. The level of the preferred cutoff varies with the Wells pretest category and whether a deep venous thrombosis is clinically suspected. D-dimer cutoffs higher than the current recommended cutoff were often preferred for patients with even moderate and high Wells categories. Compression ultrasonography accuracy had to decrease below commonly cited levels in the literature before it was not part of a preferred strategy.When pulmonary embolism is suspected in the ED, use of an enzyme-linked immunosorbent assay D-dimer assay, often at cutoffs higher than those currently in use (for patients in whom deep venous thrombosis is not clinically suspected), followed by compression ultrasonography as appropriate, can reduce costs and improve outcomes.
View details for DOI 10.1016/j.annemergmed.2010.03.029
View details for Web of Science ID 000282854500004
View details for PubMedID 20605261
Comparative Effectiveness of HIV Testing and Treatment in Highly Endemic Regions
ARCHIVES OF INTERNAL MEDICINE
2010; 170 (15): 1347-1354
Universal testing and treatment holds promise for reducing the burden of human immunodeficiency virus (HIV) in sub-Saharan Africa, but linkage from testing to treatment sites and retention in care are inadequate.We developed a simulation of the HIV epidemic and HIV disease progression in South Africa to compare the outcomes of the present HIV treatment campaign (status quo) with 4 HIV testing and treating strategies that increase access to antiretroviral therapy: (1) universal testing and treatment without changes in linkage to care and loss to follow-up; (2) universal testing and treatment with improved linkage to care; (3) universal testing and treatment with reduced loss to follow-up; and (4) comprehensive HIV care with universal testing and treatment, improved linkage to care, and reduced loss to follow-up. The main outcome measures were survival benefits, new HIV infections, and HIV prevalence.Compared with the status quo strategy, universal testing and treatment (1) was associated with a mean (95% uncertainty bounds) life expectancy gain of 12.0 months (11.3-12.2 months), and 35.3% (32.7%-37.5%) fewer HIV infections over a 10-year time horizon. Improved linkage to care (2), prevention of loss to follow-up (3), and comprehensive HIV care (4) provided substantial additional benefits: life expectancy gains compared with the status quo strategy were 16.1, 18.6, and 22.2 months, and new infections were 55.5%, 51.4%, and 73.2% lower, respectively. In sensitivity analysis, comprehensive HIV care reduced new infections by 69.7% to 76.7% under a broad set of assumptions.Universal testing and treatment with current levels of linkage to care and loss to follow-up could substantially reduce the HIV death toll and new HIV infections. However, increasing linkage to care and preventing loss to follow-up provides nearly twice the benefits of universal testing and treatment alone.
View details for Web of Science ID 000280651500010
View details for PubMedID 20696960
Cost-effective control of chronic viral diseases: Finding the optimal level of screening and contact tracing
2010; 224 (1): 35-42
Chronic viral diseases such as human immunodeficiency virus (HIV) and hepatitis B virus (HBV) afflict millions of people worldwide. A key public health challenge in managing such diseases is identifying infected, asymptomatic individuals so that they can receive antiviral treatment. Such treatment can benefit both the treated individual (by improving quality and length of life) and the population as a whole (through reduced transmission). We develop a compartmental model of a chronic, treatable infectious disease and use it to evaluate the cost and effectiveness of different levels of screening and contact tracing. We show that: (1) the optimal strategy is to get infected individuals into treatment at the maximal rate until the incremental health benefits balance the incremental cost of controlling the disease; (2) as one reduces the disease prevalence by moving people into treatment (which decreases the chance that they will infect others), one should increase the level of contact tracing to compensate for the decreased effectiveness of screening; (3) as the disease becomes less prevalent, it is optimal to spend more per case identified; and (4) the relative mix of screening and contact tracing at any level of disease prevalence is such that the marginal efficiency of contact tracing (cost per infected person found) equals that of screening if possible (e.g., when capacity limitations are not binding). We also show how to determine the cost-effective equilibrium level of disease prevalence (among untreated individuals), and we develop an approximation of the path of the optimal prevalence over time. Using this, one can obtain a close approximation of the optimal solution without having to solve an optimal control problem. We apply our methods to an example of hepatitis B virus.
View details for DOI 10.1016/j.mbs.2009.12.006
View details for Web of Science ID 000275310300005
View details for PubMedID 20043926
Cost-Effectiveness of Nationwide Hepatitis B Catch-up Vaccination Among Children and Adolescents in China
2010; 51 (2): 405-414
Liver disease and liver cancer associated with childhood-acquired chronic hepatitis B are leading causes of death among adults in China. Despite expanded newborn hepatitis B vaccination programs, approximately 20% of children under age 5 years and 40% of children aged 5 to 19 years remain unprotected from hepatitis B. Although immunizing them will be beneficial, no studies have examined the cost-effectiveness of hepatitis B catch-up vaccination in an endemic country like China. We examined the cost-effectiveness of a hypothetical nationwide free hepatitis B catch-up vaccination program in China for unvaccinated children and adolescents aged 1 to 19 years. We used a Markov model for disease progression and infections. Cost variables were based on data published by the Chinese Ministry of Health, peer-reviewed Chinese and English publications, and the GAVI Alliance. We measured costs (2008 U.S. dollars and Chinese renminbi), quality-adjusted life years, and incremental cost-effectiveness from a societal perspective. Our results show that hepatitis B catch-up vaccination for children and adolescents in China is cost-saving across a range of parameters, even for adolescents aged 15 to 19 years old. We estimate that if all 150 million susceptible children under 19 were vaccinated, more than 8 million infections and 65,000 deaths due to hepatitis B would be prevented.The adoption of a nationwide free catch-up hepatitis B vaccination program for unvaccinated children and adolescents in China, in addition to ongoing efforts to improve birth dose and newborn vaccination coverage, will be cost-saving and can generate significant population-wide health benefits. The success of such a program in China could serve as a model for other endemic countries.
View details for DOI 10.1002/hep.23310
View details for Web of Science ID 000274131200009
View details for PubMedID 19839061
- Cost-effective control of chronic viral diseases: Finding the optimal level of screening and contact tracing. Mathematical Biosciences 2010; 1 (224): 35-42.
- Cost-effectiveness of strategies for diagnosing pulmonary embolism among emergency department patients presenting with undifferentiated symptoms. Annals of Emergency Medicine 2010; 4 (56): 321-332.
- Comparative effectiveness of HIV testing and treatment in highly endemic regions. Archives of Internal Medicine 2010; 15 (17): 1347-1354.
- The cost effectiveness and population outcomes of expanded HIV screening and antiretroviral treatment in the United States. Annals of Internal Medicine 2010; 12 (153): 778-789.
- Institute of Medicine Committee on the Prevention and Control of Viral Hepatitis Infections. Hepatitis and Liver Cancer: A National Strategy for Prevention andControl of Hepatitis B and C. 2010
- Cost effectiveness of nationwide hepatitis B catchup vaccination among children and adolescents in China. Hepatology 2010; 2 (51): 405-414.
Potential population health outcomes and expenditures of HIV vaccination strategies in the United States
2009; 27 (39): 5402-5410
Estimating the potential health benefits and expenditures of a partially effective HIV vaccine is an important consideration in the debate about whether HIV vaccine research should continue. We developed an epidemic model to estimate HIV prevalence, new infections, and the cost-effectiveness of vaccination strategies in the U.S. Vaccines with modest efficacy could prevent 300,000-700,000 HIV infections and save $30 billion in healthcare expenditures over 20 years. Targeted vaccination of high-risk individuals is economically efficient, but difficulty in reaching these groups may mitigate these benefits. Universal vaccination is cost-effective for vaccines with 50% efficacy and price similar to other infectious disease vaccines.
View details for DOI 10.1016/j.vaccine.2009.06.063
View details for Web of Science ID 000269629800018
View details for PubMedID 19591796
Recommendations for Modeling Disaster Responses in Public Health and Medicine: A Position Paper of the Society for Medical Decision Making
MEDICAL DECISION MAKING
2009; 29 (4): 438-460
Mathematical and simulation models are increasingly used to plan for and evaluate health sector responses to disasters, yet no clear consensus exists regarding best practices for the design, conduct, and reporting of such models. The authors examined a large selection of published health sector disaster response models to generate a set of best practice guidelines for such models.. The authors reviewed a spectrum of published disaster response models addressing public health or health care delivery, focusing in particular on the type of disaster and response decisions considered, decision makers targeted, choice of outcomes evaluated, modeling methodology, and reporting format. They developed initial recommendations for best practices for creating and reporting such models and refined these guidelines after soliciting feedback from response modeling experts and from members of the Society for Medical Decision Making.. The authors propose 6 recommendations for model construction and reporting, inspired by the most exemplary models: health sector disaster response models should address real-world problems, be designed for maximum usability by response planners, strike the appropriate balance between simplicity and complexity, include appropriate outcomes that extend beyond those considered in traditional cost-effectiveness analyses, and be designed to evaluate the many uncertainties inherent in disaster response. Finally, good model reporting is particularly critical for disaster response models.. Quantitative models are critical tools for planning effective health sector responses to disasters. The proposed recommendations can increase the applicability and interpretability of future models, thereby improving strategic, tactical, and operational aspects of preparedness planning and response.
View details for DOI 10.1177/0272989X09340346
View details for Web of Science ID 000268291200005
View details for PubMedID 19605887
Optimal investment in HIV prevention programs: more is not always better
HEALTH CARE MANAGEMENT SCIENCE
2009; 12 (1): 27-37
This paper develops a mathematical/economic framework to address the following question: Given a particular population, a specific HIV prevention program, and a fixed amount of funds that could be invested in the program, how much money should be invested? We consider the impact of investment in a prevention program on the HIV sufficient contact rate (defined via production functions that describe the change in the sufficient contact rate as a function of expenditure on a prevention program), and the impact of changes in the sufficient contact rate on the spread of HIV (via an epidemic model). In general, the cost per HIV infection averted is not constant as the level of investment changes, so the fact that some investment in a program is cost effective does not mean that more investment in the program is cost effective. Our framework provides a formal means for determining how the cost per infection averted changes with the level of expenditure. We can use this information as follows: When the program has decreasing marginal cost per infection averted (which occurs, for example, with a growing epidemic and a prevention program with increasing returns to scale), it is optimal either to spend nothing on the program or to spend the entire budget. When the program has increasing marginal cost per infection averted (which occurs, for example, with a shrinking epidemic and a prevention program with decreasing returns to scale), it may be optimal to spend some but not all of the budget. The amount that should be spent depends on both the rate of disease spread and the production function for the prevention program. We illustrate our ideas with two examples: that of a needle exchange program, and that of a methadone maintenance program.
View details for DOI 10.1007/s10729-008-9074-7
View details for Web of Science ID 000281584100003
View details for PubMedID 19938440
- Potential population health outcomes and expenditures of HIV vaccination strategies in the United States. Vaccine 2009; 39 (27): 5402-5410.
Cost-effectiveness of voluntary HIV screening in Russia
INTERNATIONAL JOURNAL OF STD & AIDS
2009; 20 (1): 46-51
Russia has one of the world's fastest growing HIV epidemics, and HIV screening has been widespread. Whether such screening is an effective use of resources is unclear. We used epidemiologic and economic data from Russia to develop a Markov model to estimate costs, quality of life and survival associated with a voluntary HIV screening programme compared with no screening in Russia. We measured discounted lifetime health-care costs and quality-adjusted life years (QALYs) gained. We varied our inputs in sensitivity analysis. Early identification of HIV through screening provided a substantial benefit to persons with HIV, increasing life expectancy by 2.1 years and 1.7 QALYs. At a base-case prevalence of 1.2%, once-per-lifetime screening cost $13,396 per QALY gained, exclusive of benefit from reduced transmission. Cost-effectiveness of screening remained favourable until prevalence dropped below 0.04%. When HIV-transmission-related costs and benefits were included, once-per-lifetime screening cost $6910 per QALY gained and screening every two years cost $27,696 per QALY gained. An important determinant of the cost-effectiveness of screening was effectiveness of counselling about risk reduction. Early identification of HIV infection through screening in Russia is effective and cost-effective in all but the lowest prevalence groups.
View details for DOI 10.1258/ijsa.2008.008128
View details for Web of Science ID 000262962500011
View details for PubMedID 19103893
- OR’s next top model: Decision models for infectious disease control. In TutORials in Operations Research Institute for Operations Research and the Management Sciences (INFORMS). 2009: 123-138.
- Recommendations for modeling crisis response in public health and medicine: A position paper of the Society for Medical Decision Making. Medical Decision Making 2009; 4 (29): 438-460.
- Optimal investment in HIV prevention programs: More is not always better. Health Care Management Science 2009; 1 (12): 27-37.
- Cost-effectiveness of voluntary HIV screening in Russia. International Journal of STD and AIDS 2009; 1 (20): 46-51.
- Controlling Co-Epidemics: Analysis of HIV and Tuberculosis Infection Dynamics OPERATIONS RESEARCH 2008; 56 (6): 1366-1381
Modeling the logistics of response to anthrax bioterrorism
MEDICAL DECISION MAKING
2008; 28 (3): 332-350
A bioterrorism attack with an agent such as anthrax will require rapid deployment of medical and pharmaceutical supplies to exposed individuals. How should such a logistical system be organized? How much capacity should be built into each element of the bioterrorism response supply chain?The authors developed a compartmental model to evaluate the costs and benefits of various strategies for preattack stockpiling and postattack distribution and dispensing of medical and pharmaceutical supplies, as well as the benefits of rapid attack detection.The authors show how the model can be used to address a broad range of logistical questions as well as related, nonlogistical questions (e.g., the cost-effectiveness of strategies to improve patient adherence to antibiotic regimens). They generate several key insights about appropriate strategies for local communities. First, stockpiling large local inventories of medical and pharmaceutical supplies is unlikely to be the most effective means of reducing mortality from an attack, given the availability of national and regional supplies. Instead, communities should create sufficient capacity for dispensing prophylactic antibiotics in the event of a large-scale bioterror attack. Second, improved surveillance systems can significantly reduce deaths from such an attack but only if the local community has sufficient antibiotic-dispensing capacity. Third, mortality from such an attack is significantly affected by the number of unexposed individuals seeking prophylaxis and treatment. Fourth, full adherence to treatment regimens is critical for reducing expected mortality.Effective preparation for response to potential bioterror attacks can avert deaths in the event of an attack. Models such as this one can help communities more effectively prepare for response to potential bioterror attacks.
View details for DOI 10.1177/0272989X07312721
View details for Web of Science ID 000256264500006
View details for PubMedID 18349432
An ounce of prevention is worth a pound of cure: improving communication to reduce mortality during bioterrorism responses.
American journal of disaster medicine
2008; 3 (2): 65-78
To identify communication needs and evaluate the effectiveness of alternative communication strategies for bioterrorism responses.We provide a framework for evaluating communication needs during a bioterrorism response. Then, using a simulation model of a hypothetical response to anthrax bioterrorism in a large metropolitan area, we evaluate the costs and benefits of alternative strategies for communication during a response.Expected mortality increases significantly with increases in the time for attack detection and announcement; decreases in the rate at which exposed individuals seek and receive prophylaxis; increases in the number of unexposed people seeking prophylaxis; and increases in workload imbalances at dispensing centers. Thus, the timeliness, accuracy, and precision of communications about the mechanisms of exposure and instructions for obtaining prophylaxis and treatment are critical. Investment in strategies that improve adherence to prophylaxis is likely to be highly cost effective, even if the improvement in adherence is modest, and even if such strategies reduce the prophylaxis dispensing rate.Communication during the response to a bioterror attack must involve the right information delivered at the appropriate time in an effective manner from trusted sources. Because the response system for bioterror communication is only fully operationalized once an attack has occurred, tabletop planning and simulation exercises, and other up-front investments in the design of an effective communication strategy, are critical for effective response planning.
View details for PubMedID 18522248
- An ounce of prevention is worth a pound of cure: Improving communication to reduce mortality during bioterrorism responses. American Journal of Disaster Medicine 2008; 2 (3): 65-78.
INFECTIOUS DISEASE CONTROL POLICY: A ROLE FOR SIMULATION
2008 WINTER SIMULATION CONFERENCE, VOLS 1-5
View details for Web of Science ID 000274496200191
- Optimal spending on HIV prevention and treatment: A framework for evaluating the cost-effectiveness of HIV prevention and treatment programs with example application to The India AIDS Initiative. In Optimization in Medicine and Biology Taylor and Francis Publishers, Boca Raton, Florida. 2008: 147-175.
- Modeling the logistics of response to anthrax bioterrorism. Medical Decision Making 2008; 3 (28): 332-350.
- Infectious disease control policy: A role for simulation. 2008
- The cost effectiveness of counseling strategies to improve adherence to highly active antiretroviral therapy among men who have sex with men. Medical Decision Making 2008; 3 (28): 359-376.
- Controlling co-epidemics: Analysis of HIV and tuberculosis infection dynamics. Operations Research 2008; 6 (56): 1366-1381.
Contact tracing to control infectious disease: when enough is enough.
Health care management science
2007; 10 (4): 341-355
Contact tracing (also known as partner notification) is a primary means of controlling infectious diseases such as tuberculosis (TB), human immunodeficiency virus (HIV), and sexually transmitted diseases (STDs). However, little work has been done to determine the optimal level of investment in contact tracing. In this paper, we present a methodology for evaluating the appropriate level of investment in contact tracing. We develop and apply a simulation model of contact tracing and the spread of an infectious disease among a network of individuals in order to evaluate the cost and effectiveness of different levels of contact tracing. We show that contact tracing is likely to have diminishing returns to scale in investment: incremental investments in contact tracing yield diminishing reductions in disease prevalence. In conjunction with a cost-effectiveness threshold, we then determine the optimal amount that should be invested in contact tracing. We first assume that the only incremental disease control is contact tracing. We then extend the analysis to consider the optimal allocation of a budget between contact tracing and screening for exogenous infection, and between contact tracing and screening for endogenous infection. We discuss how a simulation model of this type, appropriately tailored, could be used as a policy tool for determining the appropriate level of investment in contact tracing for a specific disease in a specific population. We present an example application to contact tracing for chlamydia control.
View details for PubMedID 18074967
Cost-effectiveness of screening and vaccinating Asian and pacific islander adults for hepatitis B
ANNALS OF INTERNAL MEDICINE
2007; 147 (7): 460-469
As many as 10% of Asian and Pacific Islander adults in the United States are chronically infected with hepatitis B virus (HBV), and up to two thirds are unaware that they are infected. Without proper medical management and antiviral therapy, up to 25% of Asian and Pacific Islander persons with chronic HBV infection will die of liver disease.To assess the cost-effectiveness of 4 HBV screening and vaccination programs for Asian and Pacific Islander adults in the United States.Markov model with costs and benefits discounted at 3%.Published literature and expert opinion.Asian and Pacific Islander adults (base-case age, 40 years; sensitivity analysis conducted on ages 20 to 60 years).Lifetime.U.S. societal.A universal vaccination strategy in which all individuals are given a 3-dose vaccination series; a screen-and-treat strategy, in which individuals are given blood tests to determine whether they are chronically infected, and infected persons are monitored and treated; a screen, treat, and ring vaccinate strategy, in which all individuals are tested for chronic HBV infection and close contacts of infected persons are screened and vaccinated if needed; and a screen, treat, and vaccinate strategy, in which all individuals are tested and then vaccinated with a 3-dose series if needed. In all cases, persons found to be chronically infected are monitored and treated if indicated.Costs (2006 U.S. dollars), quality-adjusted life-years (QALYs), and incremental cost-effectiveness.Compared with the status quo, the screen-and-treat strategy has an incremental cost-effectiveness ratio of $36,088 per QALY gained. The screen, treat, and ring vaccinate strategy gains more QALYs than the screen and treat strategy and incurs modest incremental costs, leading to incremental cost-effectiveness of $39,903 per QALY gained compared with the screen and treat strategy. The universal vaccination and screen, treat, and vaccinate strategies were weakly dominated by the other 2 strategies.Over a wide range of variables, the incremental cost-effectiveness ratios of the screen and treat and screen, treat, and ring vaccinate strategies were less than $50,000 per QALY gained.Results depend on the accuracy of the underlying data and assumptions. The long-term effectiveness of new and future HBV treatments is uncertain.Screening programs for HBV among Asian and Pacific Islander adults are likely to be cost effective. Clinically significant benefits accrue from identifying chronically infected persons for medical management and vaccinating their close contacts. Such efforts can greatly reduce the burden of HBV-associated liver cancer and chronic liver disease in the Asian and Pacific Islander population.
View details for Web of Science ID 000250214700003
View details for PubMedID 17909207
Optimal mix of screening and contact tracing for endemic diseases
2007; 209 (2): 386-402
Two common means of controlling infectious diseases are screening and contact tracing. Which should be used, and when? We consider the problem of determining the cheapest mix of screening and contact tracing necessary to achieve a desired endemic prevalence of a disease or to identify a specified number of cases. We perform a partial equilibrium analysis of small-scale interventions, assuming that prevalence is unaffected by the intervention; we develop a full equilibrium analysis where we compare the long-term cost of various combinations of screening and contact tracing needed to achieve a given equilibrium prevalence; and we solve the problem of minimizing the total costs of identifying and treating disease cases plus the cost of untreated disease cases. Our analysis provides several insights. First, contact tracing is only cost effective when prevalence is below a threshold value. This threshold depends on the relative cost per case found by screening versus contact tracing. Second, for a given contact tracing policy, the screening rate needed to achieve a given prevalence or identify a specified number of cases is a decreasing function of disease prevalence. As prevalence increases above the threshold (and contact tracing is discontinued), the screening rate jumps discontinuously to a higher level. Third, these qualitative results hold when we consider unchanged or changed prevalence, and short-term or long-term costs.
View details for DOI 10.1016/j.mbs.2007.02.007
View details for Web of Science ID 000250330600004
View details for PubMedID 17428503
Planning the bioterrorism response supply chain: learn and live.
American journal of disaster medicine
2007; 2 (5): 231-247
Responses to bioterrorism require rapid procurement and distribution of medical and pharmaceutical supplies, trained personnel, and information. Thus, they present significant logistical challenges. On the basis of a review of the manufacturing and service supply chain literature, the authors identified five supply chain strategies that can potentially increase the speed of response to a bioterrorism attack, reduce inventories, and save money: effective supply chain network design; effective inventory management; postponement of product customization and modularization of component parts; coordination of supply chain stakeholders and appropriate use of incentives; and effective information management. The authors describe how concepts learned from published evaluations of manufacturing and service supply chains, as well as lessons learned from responses to natural disasters, naturally occurring outbreaks, and the 2001 US anthrax attacks, can be applied to design, evaluate, and improve the bioterrorism response supply chain. Such lessons could also be applied to the response supply chains for disease outbreaks and natural and manmade disasters.
View details for PubMedID 18491839
- Optimal mix of screening and contact tracing for endemic diseases. Mathematical Biosciences 2007; 2 (209): 386-402.
A little planning goes a long way: Multilevel allocation of HIV prevention resources
MEDICAL DECISION MAKING
2007; 27 (1): 71-81
HIV prevention funds are often allocated by decision makers at multiple levels. High-level decision makers may allocate funds to regions, and regional decision makers then allocate those funds to specific programs. Often, funds are allocated proportionally (e.g., in proportion to HIV incidence) rather than efficiently (i.e., to maximize HIV infections averted). The authors investigate the impact of efficient and proportional allocation methods at 2 different decision levels.The authors developed an optimization model of resource allocation at 2 levels-an aggregate upper level and multiple local levels-and considered efficient allocation and allocation proportional to HIV incidence. Using data from 40 U.S. states, they compared 4 strategies for allocating HIV prevention funds.The greatest health benefit (HIV infections averted) occurred when efficient allocations were made at both levels. When funds were allocated proportionally at the higher level and efficiently at the lower level, the health benefit was about 5% less than when efficient allocations were made at both levels. When funds were allocated efficiently at the higher level and proportionally at the lower level, the health benefit was 15% less than when efficient allocations were made at both levels. The least health benefit (23% less than when efficient allocations were made at both levels) occurred with proportional allocation at both levels.Efficient allocation only at the higher level cannot overcome poor allocations at lower levels. Moreover, efficient allocation at the lower level is likely to yield greater gains than efficient allocation at the higher level. Thus, upper-level decision makers, such as donor organizations, should develop incentives to promote efficient allocation by lower-level decision makers.
View details for DOI 10.1177/0272989X06297395
View details for Web of Science ID 000243911200008
View details for PubMedID 17237455
A knowledge representation of local pandemic influenza planning models.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium
Planning for pandemic flu outbreak at the small-government level can be aided through the use of mathematical policy models. Formulating and analyzing policy models, however, can be a time- and expertise-expensive process. We believe that a knowledge-based system for facilitating the instantiation of locale- and problem-specific policy models can reduce some of these costs. In this work, we present the ontology we have developed for pandemic influenza policy models.
View details for PubMedID 18694088
- Planning the bioterrorism responsesupply chain: Learn and live. American Journal of Disaster edicine 2007; 5 (2): 231-247.
- Who do you know? A simulation study of infectious disease control through contact tracing. 2007
- From Venn diagrams to bioterrorism: An OR journey. The Operations Research Center at MIT. INFORMS Topics in Operations Research Series 2007: 41-46.
- Cost effectiveness of screening and vaccinating Asian and Pacific Islander adults for hepatitis B. Annals of Internal Medicine 2007; 7 (14): 460-469.
- A little planning goes a long way: Multi-level allocation of HIV prevention resources. Medical Decision Making 2007; 1 (27): 71-81.
- Contact tracing to control infectious disease: When enough is enough. Health Care Management Science 2007; 4 (10): 341-355.
Effectiveness and cost-effectiveness of strategies to expand antiretroviral therapy in St. Petersburg, Russia
2006; 20 (17): 2207-2215
To assess the effectiveness and cost-effectiveness of treating HIV-infected injection drug users (IDUs) and non-IDUs in Russia with highly active antiretroviral therapy HAART.A dynamic HIV epidemic model was developed for a population of IDUs and non-IDUs. The location for the study was St. Petersburg, Russia. The adult population aged 15 to 49 years was subdivided on the basis of injection drug use and HIV status. HIV treatment targeted to IDUs and non-IDUs, and untargeted treatment interventions were considered. Health care costs and quality-adjusted life years (QALYs) experienced in the population were measured, and HIV prevalence, HIV infections averted, and incremental cost-effectiveness ratios of different HAART strategies were calculated.With no incremental HAART programs, HIV prevalence reached 64% among IDUs and 1.7% among non-IDUs after 20 years. If treatment were targeted to IDUs, over 40 000 infections would be prevented (75% among non-IDUs), adding 650 000 QALYs at a cost of USD 1501 per QALY gained. If treatment were targeted to non-IDUs, fewer than 10 000 infections would be prevented, adding 400 000 QALYs at a cost of USD 2572 per QALY gained. Untargeted strategies prevented the most infections, adding 950 000 QALYs at a cost of USD 1827 per QALY gained. Our results were sensitive to HIV transmission parameters.Expanded use of antiretroviral therapy in St. Petersburg, Russia would generate enormous population-wide health benefits and be economically efficient. Exclusively treating non-IDUs provided the least health benefit, and was the least economically efficient. Our findings highlight the urgency of initiating HAART for both IDUs and non-IDUs in Russia.
View details for Web of Science ID 000242676900010
View details for PubMedID 17086061
Value of quantitative D-dimer assays in identifying pulmonary embolism: Implications from a sequential decision model
ACADEMIC EMERGENCY MEDICINE
2006; 13 (7): 755-766
To examine the cost-effectiveness of a quantitative D-dimer assay for the evaluation of patients with suspected pulmonary embolism (PE) in an urban emergency department (ED).The authors analyzed different diagnostic strategies over pretest risk categories on the basis of Wells criteria by using the performance profile of the ELISA D-dimer assay (over five cutoff values) and imaging strategies used in the ED for PE: compression ultrasound (CUS), ventilation-perfusion (VQ) scan (over three cutoff values), CUS with VQ (over three cutoff values), computed tomography (CT) angiogram (CTA) with pulmonary portion (CTP) and lower-extremity venous portion, and CUS with CTP. Data used in the analysis were based on literature review. Incremental costs and quality-adjusted-life-years were the outcomes measured.Computed tomography angiogram with pulmonary portion and lower-extremity venous portion without D-dimer was the preferred strategy. CUS-VQ scanning always was dominated by CT-based strategies. When CTA was infeasible, the dominant strategy was D-dimer with CUS-VQ in moderate- and high-Wells patients and was D-dimer with CUS for low-Wells patients. When CTP specificity falls below 80%, or if its overall performance is markedly degraded, preferred strategies include D-dimer testing. Sensitivity analyses suggest that pessimistic assessments of CTP accuracy alter the results only at extremes of parameter settings.In patients in whom PE is suspected, when CTA is available, even the most sensitive quantitative D-dimer assay is not likely to be cost-effective. When CTA is not available or if its performance is markedly degraded, use of the D-dimer assay has value in combination with CUS and a pulmonary imaging study. These conclusions may not hold for the larger domain of patients presenting to the ED with chest pain or shortness of breath in whom PE is one of many competing diagnoses.
View details for DOI 10.1197/j.aem.2006.02.011
View details for Web of Science ID 000239051800008
View details for PubMedID 16723725
- Reducing mortality from anthrax bioterrorism: Strategies for stockpiling and dispensing medical and pharmaceutical supplies. Biosecurity and Bioterrorism: Biodefense Strategy, Practice, and Science 2006; 3 (4): 244-262.
Reducing mortality from anthrax bioterrorism: Strategies for stockpiling and dispensing medical and pharmaceutical supplies
BIOSECURITY AND BIOTERRORISM-BIODEFENSE STRATEGY PRACTICE AND SCIENCE
2006; 4 (3): 244-262
A critical question in planning a response to bioterrorism is how antibiotics and medical supplies should be stockpiled and dispensed. The objective of this work was to evaluate the costs and benefits of alternative strategies for maintaining and dispensing local and regional inventories of antibiotics and medical supplies for responses to anthrax bioterrorism. We modeled the regional and local supply chain for antibiotics and medical supplies as well as local dispensing capacity. We found that mortality was highly dependent on the local dispensing capacity, the number of individuals requiring prophylaxis, adherence to prophylactic antibiotics, and delays in attack detection. For an attack exposing 250,000 people and requiring the prophylaxis of 5 million people, expected mortality fell from 243,000 to 145,000 as the dispensing capacity increased from 14,000 to 420,000 individuals per day. At low dispensing capacities (<14,000 individuals per day), nearly all exposed individuals died, regardless of the rate of adherence to prophylaxis, delays in attack detection, or availability of local inventories. No benefit was achieved by doubling local inventories at low dispensing capacities; however, at higher dispensing capacities, the cost-effectiveness of doubling local inventories fell from 100,000 US dollars to 20,000 US dollars/life year gained as the annual probability of an attack increased from 0.0002 to 0.001. We conclude that because of the reportedly rapid availability of regional inventories, the critical determinant of mortality following anthrax bioterrorism is local dispensing capacity. Bioterrorism preparedness efforts directed at improving local dispensing capacity are required before benefits can be reaped from enhancing local inventories.
View details for Web of Science ID 000240714200010
View details for PubMedID 16999586
- Value of quantitative D-dimer assays in identifying pulmonary embolism: Implications from a sequential decision model. Academic Emergency Medicine 2006; 7 (13): 755-766.
- Effectiveness and cost-effectiveness of strategies to expand antiretroviral therapy in St.Petersburg, Russia. AIDS 2006; 17 (20): 2207-2215.
Improved allocation of HIV prevention resources: using information about prevention program production functions.
Health care management science
2005; 8 (1): 19-28
To allocate HIV prevention resources effectively, it is important to have information about the effectiveness of alternative prevention programs as a function of expenditure. We refer to this relationship as the "production function" for a prevention program. Few studies of HIV prevention programs have reported this relationship. This paper demonstrates the value of such information. We present a simple model for allocating HIV prevention resources, and apply the model to an illustrative HIV prevention resource allocation problem. We show that, without sufficient information about prevention program production functions, suboptimal decisions may be made. We show that epidemiologic data, such as estimates of HIV prevalence or incidence, may not provide enough information to support optimal allocation of HIV prevention resources. Our results suggest that good allocations can be obtained based on fairly basic information about prevention program production functions: an estimate of fixed cost plus a single estimate of cost and resulting risk reduction. We find that knowledge of production functions is most important when fixed cost is high and/or when the budget is a significantly constraining factor. We suggest that, at the minimum, future data collection on prevention program effectiveness should include fixed and variable cost estimates for the intervention when implemented at a "typical" level, along with a detailed description of the intervention and detailed description of costs by category.
View details for PubMedID 15782509
- Evaluating the cost effectiveness of the India AIDS Initiative: A blueprint. White Paper, Gates Foundation Policy Research Network 2005
- Global HIV prevention and treatment: Planning for the future. White Paper, Gates Foundation Policy Research Network 2005
- Modeling complex medical decision problems with the Archimedes model [Editorial]. Annals of Internal Medicine 2005; 4 (143): 303-304.
- Improved allocation of HIV prevention resources: Using information about prevention program production functions. Health Care Management Science 2005; 1 (8): 19-28.
- Regionalization of bioterrorism preparedness and response [Summary]. Evidence Report/Technology Assessment 2004: 96, 1-7.
- Allocating resources to control infectious diseases. In Operations Research and Health Care: A Handbook of Methods and Applications Kluwer Academic Publishers. 2004: 443-464.
- Operations Research and Health Care: A Handbook of Methods and Applications. edited by Brandeau, M., L., Sainfort, F., Pierskalla, W., P. Kluwer Academic Publishers, Norwell, MA. 2004
- Health care delivery: Current problems and future challenges. In Operations Research and Health Care: A Handbook of Methods and Applications Kluwer Academic Publishers. 2004: 1-14.
Resource allocation for control of infectious diseases in multiple independent populations: beyond cost-effectiveness analysis
JOURNAL OF HEALTH ECONOMICS
2003; 22 (4): 575-598
Traditional cost-effectiveness analysis (CEA) assumes that program costs and benefits scale linearly with investment-an unrealistic assumption for epidemic control programs. This paper combines epidemic modeling with optimization techniques to determine the optimal allocation of a limited resource for epidemic control among multiple noninteracting populations. We show that the optimal resource allocation depends on many factors including the size of each population, the state of the epidemic in each population before resources are allocated (e.g. infection prevalence and incidence), the length of the time horizon, and prevention program characteristics. We establish conditions that characterize the optimal solution in certain cases.
View details for DOI 10.1016/S0167-6296(03)00043-2
View details for Web of Science ID 000184078500004
View details for PubMedID 12842316
- Resource allocation for control of infectious diseases in multiple independent populations: Beyond cost-effectiveness analysis. Journal of Health Economics 2003; 4 (22): 575-598.
- Regionalization of Bioterrorism Preparedness and Response Evidence Report/Technology Assessment) Agency for Healthcare Research and Quality, Rockville, MD 2003
Dynamic resource allocation for epidemic control in multiple populations
IMA JOURNAL OF MATHEMATICS APPLIED IN MEDICINE AND BIOLOGY
2002; 19 (4): 235-255
We develop a dynamic resource allocation model in which a limited budget for epidemic control is allocated over multiple time periods to interventions that affect multiple populations. For certain special cases with two time periods, multiple independent populations, and a linear relationship between investment in a prevention programme and the resulting change in risky behaviour, we demonstrate that the optimal solution involves investing in each period as much as possible in some of the populations and nothing in all the other populations. We present heuristic algorithms for solving the general problem, and present numerical results. Our computational analyses suggest that good allocations can be made based on some fairly simple heuristics. Our analyses also suggest that allowing for some reallocation of resources over the time horizon of the problem, rather than allocating resources just once at the beginning of the time horizon, can lead to significant increases in health benefits. Allowing for reallocation of funds may generate more health benefits than use of a sophisticated model for one-time allocation of resources.
View details for Web of Science ID 000183092500001
View details for PubMedID 12828363
Optimal pricing for service facilities with self-optimizing customers
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
2002; 141 (1): 39-57
View details for Web of Science ID 000176278000004
- Optimal pricing for service facilities with self-optimizing customers. European Journal of Operational Research 2002; 1 (141): 39-57.
Difficult choices, urgent needs: Optimal investment in HIV prevention programs
QUANTIATIVE EVALUATION OF HIV PREVENTION PROGRAMS
View details for Web of Science ID 000180918400005
- Dynamic resource allocation for epidemic control in multiple populations. IMA Journal of Mathematics Applied to Medicine and Biology 2002; 4 (19): 235-255.
Optimal investment in a portfolio of HIV prevention programs
MEDICAL DECISION MAKING
2001; 21 (5): 391-408
In this article, the authors determine the optimal allocation of HIV prevention funds and investigate the impact of different allocation methods on health outcomes.The authors present a resource allocation model that can be used to determine the allocation of HIV prevention funds that maximizes quality-adjusted life years (or life years) gained or HIV infections averted in a population over a specified time horizon. They apply the model to determine the allocation of a limited budget among 3 types of HIV prevention programs in a population of injection drug users and nonusers: needle exchange programs, methadone maintenance treatment, and condom availability programs. For each prevention program, the authors estimate a production function that relates the amount invested to the associated change in risky behavior.The authors determine the optimal allocation of funds for both objective functions for a high-prevalence population and a low-prevalence population. They also consider the allocation of funds under several common rules of thumb that are used to allocate HIV prevention resources. It is shown that simpler allocation methods (e.g., allocation based on HIV incidence or notions of equity among population groups) may lead to alloctions that do not yield the maximum health benefit.The optimal allocation of HIV prevention funds in a population depends on HIV prevalence and incidence, the objective function, the production functions for the prevention programs, and other factors. Consideration of cost, equity, and social and political norms may be important when allocating HIV prevention funds. The model presented in this article can help decision makers determine the health consequences of different allocations of funds.
View details for Web of Science ID 000170925300006
View details for PubMedID 11575489
The cost-effectiveness of buprenorphine maintenance therapy for opiate addiction in the United States
2001; 96 (9): 1267-1278
To determine the cost-effectiveness of buprenorphine maintenance therapy for opiate addiction in the United States, particularly its effect on the HIV epidemic.We developed a dynamic model to capture the effects of adding buprenorphine maintenance to the current opiate dependence treatment system. We evaluated incremental costs, including all health-care costs, and incremental effectiveness, measured as quality-adjusted life years (QALYs) of survival. We considered communities with HIV prevalence among injection drug users of 5% and 40%. Because no price has been set in the United States for a dose of buprenorphine, we considered three prices per dose: $5, $15, and $30.If buprenorphine increases the number of individuals in maintenance treatment by 10%, but does not affect the number of individuals receiving methadone maintenance, the cost-effectiveness ratios for buprenorphine maintenance therapy are less than $45 000 per QALY gained for all prices, in both the low-prevalence and high-prevalence communities. If the same number of individuals enter buprenorphine maintenance (10% of the number currently in methadone), but half are injection drug users newly entering maintenance and half are individuals who switched from methadone to buprenorphine, the cost-effectiveness ratios in both communities are less than $45 000 per QALY gained for the $5 and $15 prices, and greater than $65 000 per QALY gained for the $30 price.At a price of $5 or less per dose, buprenorphine maintenance is cost-effective under all scenarios we considered. At $15 per dose, it is cost-effective if its adoption does not lead to a net decline in methadone use, or if a medium to high value is assigned to the years of life lived by injection drug users and those in maintenance therapy. At $30 per dose, buprenorphine will be cost-effective only under the most optimistic modeling assumptions.
View details for Web of Science ID 000171019400006
View details for PubMedID 11672491
Cost minimization and workload balancing in printed circuit board assembly
2001; 33 (7): 547-557
View details for Web of Science ID 000168539900002
Resource allocation for epidemic control over short time horizons
2001; 171 (1): 33-58
We present a model for allocation of epidemic control resources among a set of interventions. We assume that the epidemic is modeled by a general compartmental epidemic model, and that interventions change one or more of the parameters that describe the epidemic. Associated with each intervention is a 'production function' that relates the amount invested in the intervention to values of parameters in the epidemic model. The goal is to maximize quality-adjusted life years gained or the number of new infections averted over a fixed time horizon, subject to a budget constraint. Unlike previous models, our model allows for interacting populations and non-linear interacting production functions and does not require a long time horizon. We show that an analytical solution to the model may be difficult or impossible to derive, even for simple cases. Therefore, we derive a method of approximating the objective functions. We use the approximations to gain insight into the optimal resource allocation for three problem instances. We also develop heuristics for solving the general resource allocation problem. We present results of numerical studies using our approximations and heuristics. Finally, we discuss implications and applications of this work.
View details for Web of Science ID 000168504800003
View details for PubMedID 11325383
- Cost minimization and workload balancing in printed circuit board assembly. IIE Transactions 2001; 7 (33): 547-557.
- The cost-effectiveness of buprenorphine maintenance therapy for opiate addiction in the United States. Addiction 2001; 9 (96): 1267-1278.
- AIDS policy modeling for the 21st century: An overview of key issues. Health Care Management Science 2001; 3 (4): 165-180.
- Optimal investment in a portfolio of HIV prevention programs. Medical Decision Making 2001; 5 (21): 391-408.
- Resource allocation for epidemic control over short time horizons. Mathematical Biosciences 2001; 1 (171): 33-58.
- Difficult choices, urgent needs: Optimal investment in HIV prevention programs. In Quantitative Evaluation of HIV Prevention Programs Yale University Press, New Haven. 2001: 128-153.
The cost effectiveness of voluntary prenatal and routine newborn HIV screening in the United States
JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES
2000; 25 (5): 403-416
To evaluate the cost effectiveness of voluntary prenatal and routine postnatal HIV screening in the cohort of pregnant women and newborns in the United States.Cost-effectiveness analysis. We developed a decision model to analyze the cost effectiveness of enhanced prenatal screening and routine newborn screening for HIV. We also analyzed the incremental cost effectiveness of routine newborn screening when improved voluntary prenatal screening is already in place.Analysis of the cohort of pregnant women and newborns in the United States.Enhanced prenatal screening, or routine newborn screening for HIV.Infections averted, life expectancy, costs, and incremental cost effectiveness.Improved participation in voluntary prenatal HIV screening would result in an additional 1.1 million women being screened annually, would identify an additional 527 HIV-infected mothers annually, would avert 150 infections in newborns, and would cost $8,900 U.S. per life-year gained. Routine newborn HIV screening would test 3.9 million infants annually, would identify 1061 HIV-infected mothers, would avert 266 infections in newborns, and would cost $7,000 U.S. per life-year gained. If improved voluntary prenatal screening is already in place, routine newborn screening would avert an additional 135 infections in newborns, at an incremental cost of $10, 600 U.S. per life-year gained. The screening programs are likely to be cost effective over a wide range of assumptions regarding key factors in the analysis.Improved voluntary prenatal HIV screening of women and routine screening of newborns are cost effective. Routine newborn screening becomes less attractive as the rate of voluntary prenatal screening increases. Improved participation in voluntary prenatal screening has the added benefit that mothers maintain their right to determine whether they are tested for HIV.
View details for Web of Science ID 000166017000004
View details for PubMedID 11141240
Methadone maintenance and HIV prevention: A cost-effectiveness analysis
2000; 46 (8): 1013-1031
View details for Web of Science ID 000088961000001
HIV transmission and the cost-effectiveness of methadone maintenance
AMERICAN JOURNAL OF PUBLIC HEALTH
2000; 90 (7): 1100-1111
This study determined the cost-effectiveness of expanding methadone maintenance treatment for heroin addiction, particularly its effect on the HIV epidemic.We developed a dynamic epidemic model to study the effects of increased methadone maintenance capacity on health care costs and survival, measured as quality-adjusted life-years (QALYs). We considered communities with HIV prevalence among injection drug users of 5% and 40%.Additional methadone maintenance capacity costs $8200 per QALY gained in the high-prevalence community and $10,900 per QALY gained in the low-prevalence community. More than half of the benefits are gained by individuals who do not inject drugs. Even if the benefits realized by treated and untreated injection drug users are ignored, methadone maintenance expansion costs between $14,100 and $15,200 per QALY gained. Additional capacity remains cost-effective even if it is twice as expensive and half as effective as current methadone maintenance slots.Expansion of methadone maintenance is cost-effective on the basis of commonly accepted criteria for medical interventions. Barriers to methadone maintenance deny injection drug users access to a cost-effective intervention that generates significant health benefits for the general population.
View details for Web of Science ID 000087810000017
View details for PubMedID 10897189
- Optimal commonality in component design. Operations Research 2000; 1 (48): 1-19.
Optimal commonality in component design
2000; 48 (1): 1-19
View details for Web of Science ID 000086464300001
- Methadone maintenance and HIV prevention: A costeffectiveness analysis. Management Science 2000; 8 (46): 1013-1031.
- HIV transmission and the cost-effectiveness of methadone maintenance. American Journal of Public Health 2000; 7 (90): 1100-1111.
- The cost effectiveness of voluntary prenatal and routine newborn HIV screening in th United States. Journal of AIDS and Human Retrovirology 2000; 5 (25): 403-416.
An analysis of optimal resource allocation for prevention of infection with human immunodeficiency virus (HIV) in injection drug users and non-users
MEDICAL DECISION MAKING
1999; 19 (2): 167-179
Millions of dollars are spent annually to prevent infection with human immunodeficiency virus (HIV) without a thorough understanding of the most effective way to allocate these resources. The authors' objective was to determine the allocation of new resources among prevention programs targeted to a population of injection drug users (IDUs) and a population of non-injection drug users (non-IDUs) that would minimize the total number of incident cases of HIV infection over a given time horizon. They developed a dynamic model of HIV transmission in IDUs and non-IDUs and estimated the relationship between prevention program expenditures and reductions in HIV transmission. They evaluated three prevention programs: HIV testing with routine counseling, HIV testing with intensive counseling, and HIV testing and counseling linked to methadone maintenance programs. They modeled a low-risk IDU population (5% HIV prevalence) and a moderate-risk IDU population (10% HIV prevalence). For different available budgets, they determined the allocation of resources among the prevention programs and populations that would minimize the number of new cases of HIV infection over a five-year period, as well as the incremental value of additional prevention funds. The study framework provides a quantitative, systematic approach to funding programs to prevent HIV infection that accounts for HIV transmission dynamics, population size, and the costs and effectiveness of the interventions in reducing HIV transmission. The approach is general and can be used to evaluate a broader group of prevention programs and risk populations. This framework thus could enable policy makers and clinicians to identify a portfolio of programs that provide, collectively, the most benefit for a given budget.
View details for Web of Science ID 000079539000007
View details for PubMedID 10231079
- An analysis of optimal resource allocation for prevention of infection with human immunodeficiency virus in jection drug users and non-users. Medical Decision Making, 1999; 2 (19): 167-179.
Design of an automated shop floor material handling system with inventory considerations
1999; 47 (1): 65-80
View details for Web of Science ID 000082320600008
- Design of an automated shop floor material handling system with inventory considerations. Operations Research 1999; 1 (47): 65-80
The effects of protease inhibitors on the spread of HIV and the development of drug-resistant HIV strains: A simulation study
1998; 71 (4): 262-275
View details for Web of Science ID 000078219200006
Optimal component assignment and board grouping in printed circuit board manufacturing
1998; 46 (5): 675-689
View details for Web of Science ID 000084981000006
Effect of relapse to high-risk behavior on the costs and benefits of a program to screen women for human immunodeficiency virus
1998; 28 (3): 52-74
View details for Web of Science ID 000075316200005
OR modeling and AIDS policy: From theory to practice
1998; 28 (3): 3-22
View details for Web of Science ID 000075316200002
- OR modeling and AIDS policy: From theory to practice. Interfaces 1998; 3 (28): 3-22.
Note. Optimal storage assignment policies for automated storage and retrieval systems with stochastic demands
1998; 44 (1): 142-148
View details for Web of Science ID 000072627200009
Simulating the effects of protease inhibitors on the HIV epidemic: Treatment, compliance, and drug resistance
PROCEEDINGS OF THE 1998 MEDICAL SCIENCES SIMULATION CONFERENCE
View details for Web of Science ID 000082161100011
Using simulation to find optimal funding levels for HIV prevention programs with different costs and effectiveness
PROCEEDINGS OF THE 1998 MEDICAL SCIENCES SIMULATION CONFERENCE
View details for Web of Science ID 000082161100010
- Effects of relapse to high-risk behavior on the costs andbenefits of a voluntary program to screen women for HIV. Interfaces 1998; 3 (28): 52-74.
- Note: Optimal storage assignment policies for automated storage and retrieval systems with stochastic demands. Management Science 1998; 1 (44): 142-148.
- Using simulation to find optimal funding levels for HIV prevention programs with different costs and effectiveness. 1998
- Optimal component assignment and board grouping in printed circuit board manufacturing. Operations Research 1998; 5 (46): 675-689.
- The effects of protease inhibitors on the spread of HIV and the development of drug-resistant HIV strains: A simulation study. Simulation 1998; 4 (71): 262-275.
- AIDS policy modeling: A social role for operations research. Ricerca Operativa 1998; 81-82 (27): 5-33
- Simulating the effects of protease inhibitors on the HIV epidemic: Treatment, compliance, and drug resistance. 1998
Designing a zoned automated guided vehicle system with multiple vehicles and multiple load capacity
1997; 45 (6): 857-873
View details for Web of Science ID 000071690800007
- Review of Network and Discrete Location – Models, Algorithms, and Applications by M.S. Daskin. Interfaces 1997; 1 (27): 157-158.
- Designing a zoned automated guided vehicle system with multiple vehicles and multiple load capacity. Operations Research 1997; 6 (45): 857-873.
Stochastic modeling for automated material handling system design and control
1996; 30 (4): 330-350
View details for Web of Science ID A1996VX47400005
Designing a single-vehicle automated guided vehicle system with multiple load capacity
1996; 30 (4): 351-363
View details for Web of Science ID A1996VX47400006
- Designing a single-vehicle automated guided vehicle system with multiple load capacity. Transportation Science 1996; 4 (30): 351-363.
- Policy analysis of preventive HIV interventions targeted to adolescents. 1996
- Stochastic modeling for automated material handling systemdesign and control. Transportation Science 1996; 4 (30): 330-350.
- Designing multiple-load automated guided vehicle systems for delivering material from a central depot. Transactions of the ASME: Journal of Engineering for Industry 1995; 1 (117): 33-41.
- Location with market externalities. In Facility Location: A Survey of Applications and Methods Springer-Verlag, New York, NY. 1995: 121-150.
AN ANALYTIC MODEL FOR DESIGN AND ANALYSIS OF SINGLE-VEHICLE ASYNCHRONOUS MATERIAL HANDLING SYSTEMS
1994; 28 (4): 337-353
View details for Web of Science ID A1994PT89800006
AN APPROACH FOR WORST-CASE ANALYSIS OF HEURISTICS - ANALYSIS OF A FLEXIBLE 0-1 KNAPSACK-PROBLEM
JOURNAL OF THE OPERATIONS RESEARCH SOCIETY OF JAPAN
1994; 37 (3): 197-210
View details for Web of Science ID A1994QF81100004
LOCATION OF COMPETING FACILITIES IN A USER-OPTIMIZING ENVIRONMENT WITH MARKET EXTERNALITIES
1994; 28 (2): 125-140
View details for Web of Science ID A1994NM18300004
- AIDS policy modeling by example. AIDS 1994; Suppl 1 (8): S333-S340.
WHEN WOMEN RETURN TO RISK - COSTS AND BENEFITS OF HIV SCREENING IN THE PRESENCE OF RELAPSE
RAVEN PRESS. 1994: 121-136
View details for Web of Science ID A1994BA41L00007
- An analytic model for design and analysis of single-vehicle asynchronous material handling systems. Transportation Science 1994; 4 (28): 337-353.
- When women return to risk: Costs and benefits of HIV screening in the presence of relapse. In Modeling the AIDS Epidemic: Planning, Policy and Prediction Raven Press, New York, NY. 1994: 121-136
- An approach for worst case analysis of heuristics: Analysis of a flexible 0-1 knapsack problem. Journal of the Operations Research Society of Japan 1994; 3 (37): 197-210.
- Location of competing facilities in a user-optimizing environment with market externalities. Transportation Science 1994; 2 (28): 125-140.
- Facility location in a user-optimizing environment with market externalities: Analysis of customer equilibria and optimal public facility locations. Location Science 1994; 3 (2): 129-147.
- Modeling the AIDS Epidemic: Planning, Policy and Prediction. edited by Kaplan, E., H., Brandeau, M., L. Raven Press, New York, NY. 1994
AN ANALYTIC MODEL FOR DESIGN OF A MULTIVEHICLE AUTOMATED GUIDED VEHICLE SYSTEM
1993; 39 (12): 1477-1489
View details for Web of Science ID A1993MQ37900004
- Application of analytic models for material handling system design: Analysis of stochastic effects. In Progress in Material Handling Research, Braun-Brumfield, Inc., Ann Arbor, MI 1993: 97-120
SCREENING WOMEN OF CHILDBEARING AGE FOR HUMAN-IMMUNODEFICIENCY-VIRUS - A MODEL-BASED POLICY ANALYSIS
1993; 39 (1): 72-92
View details for Web of Science ID A1993KM62000006
- Sequential location and allocation: Worst case performance and statistical estimation. Location Science 1993; 4 (1): 289-298
- Screening women of childbearing age for human immunodeficiency virus: A model-based policy analysis. Management Science 1993; 1 (39): 72-92.
- PR for OR/MS: How can you get involved? OR/MS Today 1993: 68-69.
- An analytic model for design of a multivehicle automated guided vehicle system. Management Science 1993; 12 (39): 1477-1489.
- Strategic production planning: Operation assignment and product grouping. 1993
SCREENING WOMEN OF CHILDBEARING AGE FOR HUMAN-IMMUNODEFICIENCY-VIRUS - A COST-BENEFIT-ANALYSIS
ARCHIVES OF INTERNAL MEDICINE
1992; 152 (11): 2229-2237
In light of the increasing problem of perinatal human immunodeficiency virus (HIV) transmission, the issue of screening women for HIV is receiving considerable attention. We analyzed the costs and benefits of screening women of childbearing age for HIV. The analysis was based on a dynamic model of the HIV epidemic that incorporated disease transmission and progression, behavioral changes, and effects of screening and counseling. We found that the primary benefit of screening programs targeted to women of childbearing age lies not in the prevention of HIV infection in their newborns but in the prevention of infection in their adult contacts. Because of this benefit, screening medium- and high-risk women is likely to be cost-beneficial over a wide range of assumptions about program cost and behavioral changes in response to screening.
View details for Web of Science ID A1992JX15100008
View details for PubMedID 1444682
CHARACTERIZATION OF THE STOCHASTIC MEDIAN QUEUE TRAJECTORY IN A PLANE WITH GENERALIZED DISTANCES
1992; 40 (2): 331-341
View details for Web of Science ID A1992HP30800010
- AIDS: Thoughts on managing a deadly epidemic. OR/MS Today. 1992: 50-52.
- A center location problem with congestion. Annals of Operations Research 1992; 1 (40): 17-32.
- Application of analytic models for material handling system design: Analysis of stochastic effects. 1992
- Screening women of childbearing age for human immunodeficiency virus: A cost-benefit analysis. Archives of Internal Medicine 1992; 11 (152): 2229-2237
- Characterization of the stochastic queue median trajectory in a plane with generalized distances. Operations Research 1992; 2 (40): 331-341.
- Integrated design and control of automated guided vehicle systems. Planning and Control of Material Handling Systems American Society of Manufacturing Engineers. 1992: 17-32.
- Analytical models for design of automated guided vehicle systems. 1992
A POLICY MODEL OF HUMAN-IMMUNODEFICIENCY-VIRUS SCREENING AND INTERVENTION
1991; 21 (3): 5-25
View details for Web of Science ID A1991FR52300002
DESIGN OF MANUFACTURING CELLS - OPERATION ASSIGNMENT IN PRINTED-CIRCUIT BOARD MANUFACTURING
JOURNAL OF INTELLIGENT MANUFACTURING
1991; 2 (2): 95-106
View details for Web of Science ID A1991FJ53200005
PARAMETRIC ANALYSIS OF OPTIMAL FACILITY LOCATIONS
1991; 21 (2): 223-243
View details for Web of Science ID A1991EY92300006
- A policy model of human immunodeficiency virus screening and intervention. Interfaces 1991; 3 (21): 5-25.
- Parametric analysis of optimal facility locations. Networks 1991; 2 (21): 223-243.
- Design of manufacturing cells: Operation assignment in printed circuit board manufacturing. Journal of Intelligent Manufacturing, 1991; 2 (2): 95-106
- HIV testing of pregnant women and newborns [Letter]. Journal of the American Medical Association 1991; 265: 1525
A UNIFIED FAMILY OF SINGLE-SERVER QUEUING LOCATION MODELS
1990; 38 (6): 1034-1044
View details for Web of Science ID A1990EW40100009
TRAJECTORY ANALYSIS OF THE STOCHASTIC QUEUE MEDIAN IN A PLANE WITH RECTILINEAR DISTANCES
1990; 24 (3): 230-243
View details for Web of Science ID A1990DR78300006
- A unified family of single-server queuing location models. Operations Research 1990; 6 (38): 1034-1044.
- Trajectory analysis of the stochastic queue median in a plane with rectilinear distances. Transportation Science 1990; 3 (24): 230-243
- Policy analysis of human immunodeficiency virus screening and intervention: An overview of modeling approaches. AIDS and Public Policy Journal 1990; 3 (5): 119-131.
AN OVERVIEW OF REPRESENTATIVE PROBLEMS IN LOCATION RESEARCH
1989; 35 (6): 645-674
View details for Web of Science ID A1989AE55800001
- An overview of representative problems in location research [Extended abstract]. OR/MS Today 1989: 57-58.
- An overview of representative problems in location research. Management Science 1989; 6 (35): 645-674
- Review of Operations Management for Distributed Service Networks by N. Ahituv and O. Berman. Interfaces 1989: 84-86.
- A mathematical model of AIDS screening. Stanford Engineering 1989: 8-15.
PARAMETRIC FACILITY LOCATION ON A TREE NETWORK WITH AN LP-NORM COST FUNCTION
1988; 22 (1): 59-69
View details for Web of Science ID A1988M301600006
- Establishing continuity of certain optimal parametric facility location trajectories. Transportation Science 1988; 3 (22): 224-225.
- Parametric facility location on a tree network with an Lp norm cost function. Transportation Science 1988; 1 (22): 59-69.
AN INTEGRATED BUDGET MODEL FOR MEDICAL-SCHOOL FINANCIAL-PLANNING
1987; 35 (5): 684-703
View details for Web of Science ID A1987M514500003
- The workup of the asymptomatic patient with a positive fecal occult blood test. Medical Decision Making 1987; 1 (7): 32-46.
THE WORKUP OF THE ASYMPTOMATIC PATIENT WITH A POSITIVE FECAL OCCULT BLOOD-TEST
MEDICAL DECISION MAKING
1987; 7 (1): 32-46
Twenty-two protocols for working up an asymptomatic patient who has a positive fecal occult blood test were evaluated using existing information on the prevalences of cancers, adenomas and other conditions in such patients; the natural history of colorectal cancer; the effectiveness of screening tests; risks; and costs. The authors estimate the impacts of the 22 workup strategies on outcomes such as the chance of finding an existing cancer or adenoma, risks (bleeding and perforation), and financial costs of different strategies involving rigid sigmoidoscopy, flexible sigmoidoscopy, barium enema, and colonoscopy. Two protocols were particularly effective. The first involves performing a barium enema study and following it with colonoscopy; if colonoscopy is negative, the barium enema study should be repeated. The second is to perform colonoscopy and if it is negative, follow it with a barium enema study.
View details for Web of Science ID A1987F586400008
View details for PubMedID 3100902
- An integrated budget model for medical school financial planning. Operations Research 1987; 5 (35): 684-703.
- Extending and applying the Hypercube Queueing Model to deploy ambulances in Boston. In Management Science and the Delivery of Urban Service, Vol. 22, 121-154, North- Holland/Elsevier, 1986. TIMS Studies in the Management Sciences Series, North-Holland/Elsevier,. 1986: 121-154
- Locating the two-median of a tree network with continuous link demands. Annals of Operations Research 1986; 7 (6): 223-253.
- A patient mix model for hospital financial planning Inquiry 1984; 1 (21): 32-44
A PATIENT MIX MODEL FOR HOSPITAL FINANCIAL-PLANNING
INQUIRY-THE JOURNAL OF HEALTH CARE ORGANIZATION PROVISION AND FINANCING
1984; 21 (1): 32-44
A linear programming model was formulated to examine the impact on hospital finances and resource use of changes in patient mix under current and proposed government reimbursement regulations. The model specifically incorporated the costs, revenues, and resource consumption patterns associated with patients drawn from different intensity level and payer class combinations. The necessary data were obtained from financial reports and other records, and the model was used in policy analysis at a major university teaching hospital.
View details for Web of Science ID A1984TQ78500004
View details for PubMedID 6232215
- A National Assessment of Police Command, Control, and Communications Systems. National Institute of Justice, Washington, DC 1983