My work broadly investigates the drivers of population health improvements in developing countries. I study how economic, political, and natural environments affect population health. I use a mix of experimental, econometric, qualitative, modeling, and demographic tools to produce insights and strategies for improving health. A sample of current projects address the following questions:
•What role does US foreign aid play in reducing mortality and improving equity in developing countries?
•What forms of engagement in health improvements - social marketing, public health interventions, or community empowerment, for example - work, and which do not?
•What effect do malaria control programs have on child mortality?
•What combination of prevention strategies are most cost-effective for Africa’s HIV epidemic?
•What is the evidence that foreign aid for health is good diplomacy?
•Which populations are most vulnerable to the effects of climate conditions on the availability of food?
- Infectious Disease
Boards, Advisory Committees, Professional Organizations
Faculty Fellow, Center for Innovation in Global Health (2015 - Present)
Fellowship:Stanford Hospital and Clinics (2009) CA
Residency:Stanford Hospital and Clinics (2005) CA
Medical Education:Harvard Medical School (2001) MA
Internship:Hospital of the University of Pennsylvania (2004) PA
Residency:Hospital of the University of Pennsylvania (2004) PA
Board Certification: Infectious Disease, American Board of Internal Medicine (2008)
MS, Stanford University, Health Services Research (2009)
Current Research and Scholarly Interests
My research interests involve understanding the relationship between policies and health outcomes in developing countries. I explore how decisions about foreign assistance for health are made, and how those decisions affect health and health delivery systems in recipient countries. I further explore issues of resource allocation in low and middle-income countries through disease modeling and cost-effectiveness analyses.
- Microbes and Society
OSPSANTG 60 (Aut)
- Outcomes Analysis
BIOMEDIN 251, HRP 252, MED 252 (Spr)
Independent Studies (14)
- DDRL Independent Study-Work with Adviser
DDRL 191 (Aut, Win)
- Directed Reading in Environment and Resources
ENVRES 398 (Aut, Win, Spr, Sum)
- Directed Reading in Health Research and Policy
HRP 299 (Aut, Win, Spr, Sum)
- Directed Reading in Medicine
MED 299 (Aut, Win, Spr, Sum)
- Directed Research in Environment and Resources
ENVRES 399 (Aut, Win, Spr, Sum)
- Early Clinical Experience in Medicine
MED 280 (Aut, Win, Spr, Sum)
- Graduate Research
HRP 399 (Aut, Spr, Sum)
- Graduate Research
MED 399 (Aut, Win, Spr, Sum)
HUMBIO 194 (Aut, Win, Spr)
- Indep. Study: Global Health, Epidemiology and History
OSPSANTG 61B (Aut)
- Independent Study: Health and Environment
OSPSANTG 61A (Aut)
- Medical Scholars Research
MED 370 (Aut, Win, Spr, Sum)
- Research in Human Biology
HUMBIO 193 (Aut, Win)
- Undergraduate Research
MED 199 (Aut, Win, Spr, Sum)
- DDRL Independent Study-Work with Adviser
Prior Year Courses
- Analysis of Costs, Risks, and Benefits of Health Care
BIOMEDIN 432, HRP 392 (Aut)
- Outcomes Analysis
BIOMEDIN 251, HRP 252, MED 252 (Spr)
- Outcomes Analysis
BIOMEDIN 251, HRP 252, MED 252 (Spr)
- Outcomes Analysis
BIOMEDIN 251, HRP 252, MED 252 (Spr)
- Analysis of Costs, Risks, and Benefits of Health Care
Doctoral Dissertation Reader (AC)
Sung Eun Choi, Allison Pitt, Christopher Weyant
Postdoctoral Faculty Sponsor
Aleksandra Jakubowski, Zachary Wagner-Rubin
Doctoral Dissertation Advisor (AC)
Doctoral Dissertation Co-Advisor (AC)
Postdoctoral Research Mentor
Aleksandra Jakubowski, Zachary Wagner-Rubin
Sources of variation in under-5 mortality across sub-Saharan Africa: a spatial analysis.
The Lancet. Global health
Detailed spatial understanding of levels and trends in under-5 mortality is needed to improve the targeting of interventions to the areas of highest need, and to understand the sources of variation in mortality. To improve this understanding, we analysed local-level information on child mortality across sub-Saharan Africa between 1980-2010.We used data from 82 Demographic and Health Surveys in 28 sub-Saharan African countries, including the location and timing of 3·24 million childbirths and 393 685 deaths, to develop high-resolution spatial maps of under-5 mortality in the 1980s, 1990s, and 2000s. These estimates were at a resolution of 0·1 degree latitude by 0·1 degree longitude (roughly 10 km × 10 km). We then analysed this spatial information to distinguish within-country versus between-country sources of variation in mortality, to examine the extent to which declines in mortality have been accompanied by convergence in the distribution of mortality, and to study localised drivers of mortality differences, including temperature, malaria burden, and conflict.In our sample of sub-Saharan African countries from the 1980s to the 2000s, within-country differences in under-5 mortality accounted for 74-78% of overall variation in under-5 mortality across space and over time. Mortality differed significantly across only 8-15% of country borders, supporting the role of local, rather than national, factors in driving mortality patterns. We found that by the end of the study period, 23% of the eligible children in the study countries continue to live in mortality hotspots-areas where, if current trends continue, the Sustainable Developent Goals mortality targets will not be met. In multivariate analysis, within-country mortality levels at each pixel were significantly related to local temperature, malaria burden, and recent history of conflict.Our findings suggest that sub-national determinants explain a greater portion of under-5 mortality than do country-level characteristics. Sub-national measures of child mortality could provide a more accurate, and potentially more actionable, portrayal of where and why children are still dying than can national statistics.The Stanford Woods Institute for the Environment.
View details for DOI 10.1016/S2214-109X(16)30212-1
View details for PubMedID 27793587
Health Aid Is Allocated Efficiently, But Not Optimally: Insights From A Review Of Cost-Effectiveness Studies.
2015; 34 (7): 1188-1195
Development assistance from high-income countries to the health sectors of low- and middle-income countries (health aid) is an important source of funding for health in low- and middle-income countries. However, the relationship between health aid and the expected health improvements from those expenditures-the cost-effectiveness of targeted interventions-remains unknown. We reviewed the literature for cost-effectiveness of interventions targeting five disease categories: HIV; malaria; tuberculosis; noncommunicable diseases; and maternal, newborn, and child health. We measured the alignment between health aid and cost-effectiveness, and we examined the possibility of better alignment by simulating health aid reallocation. The relationship between health aid and incremental cost-effectiveness ratios is negative and significant: More health aid is going to disease categories with more cost-effective interventions. Changing the allocation of health aid earmarked funding could lead to greater health gains even without expanding overall disbursements. The greatest improvements in the alignment would be achieved by reallocating some aid from HIV or maternal, newborn, and child health to malaria or TB. We conclude that health aid is generally aligned with cost-effectiveness considerations, but in some countries this alignment could be improved.
View details for DOI 10.1377/hlthaff.2015.0001
View details for PubMedID 26153314
Changes in Child Mortality Over Time Across the Wealth Gradient in Less-Developed Countries
2014; 134 (6): E1551-E1559
It is unknown whether inequalities in under-5 mortality by wealth in low- and middle-income countries (LMICs) are growing or declining.All Demographic and Health Surveys conducted between 2002 and 2012 were used to measure under-5 mortality trends in 3 wealth tertiles. Two approaches were used to estimate changes in under-5 mortality: within-survey changes from all 54 countries, and between-survey changes for 29 countries with repeated survey waves. The principal outcome measures include annual decline in mortality, and the ratio of mortality between the poorest and least-poor wealth tertiles.Mortality information in 85 surveys from 929 224 households and 1 267 167 women living in 54 countries was used. In the subset of 29 countries with repeat surveys, mortality declined annually by 4.36, 3.36, and 2.06 deaths per 1000 live births among the poorest, middle, and least-poor tertiles, respectively (P = .031 for difference). The mortality ratio declined from 1.68 to 1.48 during the study period (P = .006 for trend). In the complete set of 85 surveys, the mortality ratio declined in 64 surveys (from 2.11 to 1.55), and increased in 21 surveys (from 1.58 to 1.88). Multivariate analyses suggest that convergence was associated with good governance (P ≤ .03 for 4 governance indicators: government effectiveness, rule of law, regulatory quality, and control of corruption).Overall, under-5 mortality in low- and middle-income countries has decreased faster among the poorest compared with the least poor between 1995 and 2012, but progress in some countries has lagged, especially with poor governance.
View details for DOI 10.1542/peds.2014-2320
View details for Web of Science ID 000345844200006
View details for PubMedID 25384496
HIV Development Assistance and Adult Mortality in Africa
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
2012; 307 (19): 2060-2067
The effect of global health initiatives on population health is uncertain. Between 2003 and 2008, the US President's Emergency Plan for AIDS Relief (PEPFAR), the largest initiative ever devoted to a single disease, operated intensively in 12 African focus countries. The initiative's effect on all-cause adult mortality is unknown.To determine whether PEPFAR was associated with relative changes in adult mortality in the countries and districts where it operated most intensively.Using person-level data from the Demographic and Health Surveys, we conducted cross-country and within-country analyses of adult mortality (annual probability of death per 1000 adults between 15 and 59 years old) and PEPFAR's activities. Across countries, we compared adult mortality in 9 African focus countries (Ethiopia, Kenya, Mozambique, Namibia, Nigeria, Rwanda, Tanzania, Uganda, and Zambia) with 18 African nonfocus countries from 1998 to 2008. We performed subnational analyses using information on PEPFAR's programmatic intensity in Tanzania and Rwanda. We employed difference-in-difference analyses with fixed effects for countries and years as well as personal and time-varying area characteristics.Adult all-cause mortality.We analyzed information on 1 538 612 adults, including 60 303 deaths, from 41 surveys in 27 countries, 9 of them focus countries. In 2003, age-adjusted adult mortality was 8.3 per 1000 adults in the focus countries (95% CI, 8.0-8.6) and 8.5 per 1000 adults (95% CI, 8.3-8.7) in the nonfocus countries. In 2008, mortality was 4.1 per 1000 (95% CI, 3.6-4.6) in the focus countries and 6.9 per 1000 (95% CI, 6.3-7.5) in the nonfocus countries. The adjusted odds ratio of mortality among adults living in focus countries compared with nonfocus countries between 2004 and 2008 was 0.84 (95% CI, 0.72-0.99; P = .03). Within Tanzania and Rwanda, the adjusted odds ratio of mortality for adults living in districts where PEPFAR operated more intensively was 0.83 (95% CI, 0.72-0.97; P = .02) and 0.75 (95% CI, 0.56-0.99; P = .04), respectively, compared with districts where it operated less intensively.Between 2004 and 2008, all-cause adult mortality declined more in PEPFAR focus countries relative to nonfocus countries. It was not possible to determine whether PEPFAR was associated with mortality effects separate from reductions in HIV-specific deaths.
View details for Web of Science ID 000304048200025
View details for PubMedID 22665105
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
- The US Global Health Initiative Informing Policy With Evidence JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION 2010; 304 (7): 791-792
Differentiated Human Immunodeficiency Virus RNA Monitoring in Resource-Limited Settings: An Economic Analysis.
Clinical infectious diseases
2017; 64 (12): 1724-1730
Viral load (VL) monitoring for patients receiving antiretroviral therapy (ART) is recommended worldwide. However, the costs of frequent monitoring are a barrier to implementation in resource-limited settings. The extent to which personalized monitoring frequencies may be cost-effective is unknown.We created a simulation model parameterized using person-level longitudinal data to assess the benefits of flexible monitoring frequencies. Our data-driven model tracked human immunodeficiency virus (HIV)-infected individuals for 10 years following ART initiation. We optimized the interval between viral load tests as a function of patients' age, gender, education, duration since ART initiation, adherence behavior, and the cost-effectiveness threshold. We compared the cost-effectiveness of the personalized monitoring strategies to fixed monitoring intervals every 1, 3, 6, 12, and 24 months.Shorter fixed VL monitoring intervals yielded increasing benefits (6.034 to 6.221 discounted quality-adjusted life-years [QALYs] per patient with monitoring every 24 to 1 month over 10 years, respectively, standard error = 0.005 QALY), at increasing average costs: US$3445 (annual monitoring) to US$5393 (monthly monitoring) per patient, respectively (standard error = US$3.7). The adaptive policy optimized for low-income contexts achieved 6.142 average QALYs at a cost of US$3524, similar to the fixed 12-month policy (6.135 QALYs, US$3518). The adaptive policy optimized for middle-income resource settings yields 0.008 fewer QALYs per person, but saves US$204 compared to monitoring every 3 months.The benefits from implementing adaptive vs fixed VL monitoring policies increase with the availability of resources. In low- and middle-income countries, adaptive policies achieve similar outcomes to simpler, fixed-interval policies.
View details for DOI 10.1093/cid/cix177
View details for PubMedID 28329208
Disease ecology, health and the environment: a framework to account for ecological and socio-economic drivers in the control of neglected tropical diseases
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
2017; 372 (1722)
Reducing the burden of neglected tropical diseases (NTDs) is one of the key strategic targets advanced by the Sustainable Development Goals. Despite the unprecedented effort deployed for NTD elimination in the past decade, their control, mainly through drug administration, remains particularly challenging: persistent poverty and repeated exposure to pathogens embedded in the environment limit the efficacy of strategies focused exclusively on human treatment or medical care. Here, we present a simple modelling framework to illustrate the relative role of ecological and socio-economic drivers of environmentally transmitted parasites and pathogens. Through the analysis of system dynamics, we show that periodic drug treatments that lead to the elimination of directly transmitted diseases may fail to do so in the case of human pathogens with an environmental reservoir. Control of environmentally transmitted diseases can be more effective when human treatment is complemented with interventions targeting the environmental reservoir of the pathogen. We present mechanisms through which the environment can influence the dynamics of poverty via disease feedbacks. For illustration, we present the case studies of Buruli ulcer and schistosomiasis, two devastating waterborne NTDs for which control is particularly challenging.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'.
View details for DOI 10.1098/rstb.2016.0128
View details for Web of Science ID 000399956400009
View details for PubMedID 28438917
Effect of Meat Price on Race and Gender Disparities in Obesity, Mortality and Quality of Life in the US: A Model-Based Analysis
2017; 12 (1)
There are large differences in the burden and health implications of obesity by race and gender in the US. It is unclear to what extent policies modifying caloric consumption change the distribution of the burden of obesity and related health outcomes. Meat is a large component of the American diet. We investigate how changing meat prices (that may result from policies or from exogenous factors that reduce supply) might impact the burden of obesity by race and gender.We construct a microsimulation model that evaluates the 15-year body-mass index (BMI) and mortality impact of changes in meat price (5, 10, 25, and 50% increase) in the US adult population stratified by age, gender, race, and BMI.Under each price change evaluated, relative to the status quo, white males, black males, and black females are expected to realize more dramatic reduction in 2030 obesity prevalence than white females. Life expectancy gains are also projected to differ by subpopulation, with black males far less likely to benefit from an increase in meat prices than other groups.Changing meat prices has considerable potential to affect population health differently by race and gender. In designing interventions that alter the price of foods to consumers, it is not sufficient to assess health effects based solely on the population as a whole, since differential effects across subpopulations may be substantial.
View details for DOI 10.1371/journal.pone.0168710
View details for Web of Science ID 000391612300047
View details for PubMedID 28045931
View details for PubMedCentralID PMC5207744
Mortality along the continuum of HIV care in Rwanda: a model-based analysis
BMC INFECTIOUS DISEASES
HIV is the leading cause of death among adults in sub-Saharan Africa. However, mortality along the HIV care continuum is poorly described. We combine demographic, epidemiologic, and health services data to estimate where are people with HIV dying along Rwanda's care continuum.We calibrated an age-structured HIV disease and transmission stochastic simulation model to the epidemic in Rwanda. We estimate mortality among HIV-infected individuals in the following states: untested, tested without establishing care in an antiretroviral therapy (ART) program (unlinked), in care before initiating ART (pre-ART), lost to follow-up (LTFU) following ART initiation, and retained in active ART care. We estimated mortality among people living with HIV in Rwanda through 2025 under current conditions, and with improvements to the HIV care continuum.In 2014, the greatest portion of deaths occurred among those untested (35.4%), followed by those on ART (34.1%), reflecting the large increase in the population on ART. Deaths among those LTFU made up 11.8% of all deaths among HIV-infected individuals in 2014, and in the base case this portion increased to 18.8% in 2025, while the contribution to mortality declined among those untested, unlinked, and in pre-ART. In our model only combined improvements to multiple aspects of the HIV care continuum were projected to reduce the total number of deaths among those with HIV, estimated at 8177 in 2014, rising to 10,659 in the base case, and declining to 5,691 with combined improvements in 2025.Mortality among those untested for HIV contributes a declining portion of deaths among HIV-infected individuals in Rwanda, but the portion of deaths among those LTFU is expected to increase the most over the next decade. Combined improvements to the HIV care continuum might be needed to reduce the number of deaths among those with HIV.
View details for DOI 10.1186/s12879-016-2052-7
View details for Web of Science ID 000389084100001
View details for PubMedID 27905895
Feasibility of achieving the 2025 WHO global tuberculosis targets in South Africa, China, and India: a combined analysis of 11 mathematical models.
The Lancet. Global health
2016; 4 (11): e806-e815
The post-2015 End TB Strategy proposes targets of 50% reduction in tuberculosis incidence and 75% reduction in mortality from tuberculosis by 2025. We aimed to assess whether these targets are feasible in three high-burden countries with contrasting epidemiology and previous programmatic achievements.11 independently developed mathematical models of tuberculosis transmission projected the epidemiological impact of currently available tuberculosis interventions for prevention, diagnosis, and treatment in China, India, and South Africa. Models were calibrated with data on tuberculosis incidence and mortality in 2012. Representatives from national tuberculosis programmes and the advocacy community provided distinct country-specific intervention scenarios, which included screening for symptoms, active case finding, and preventive therapy.Aggressive scale-up of any single intervention scenario could not achieve the post-2015 End TB Strategy targets in any country. However, the models projected that, in the South Africa national tuberculosis programme scenario, a combination of continuous isoniazid preventive therapy for individuals on antiretroviral therapy, expanded facility-based screening for symptoms of tuberculosis at health centres, and improved tuberculosis care could achieve a 55% reduction in incidence (range 31-62%) and a 72% reduction in mortality (range 64-82%) compared with 2015 levels. For India, and particularly for China, full scale-up of all interventions in tuberculosis-programme performance fell short of the 2025 targets, despite preventing a cumulative 3·4 million cases. The advocacy scenarios illustrated the high impact of detecting and treating latent tuberculosis.Major reductions in tuberculosis burden seem possible with current interventions. However, additional interventions, adapted to country-specific tuberculosis epidemiology and health systems, are needed to reach the post-2015 End TB Strategy targets at country level.Bill and Melinda Gates Foundation.
View details for DOI 10.1016/S2214-109X(16)30199-1
View details for PubMedID 27720688
Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models.
The Lancet. Global health
2016; 4 (11): e816-e826
The post-2015 End TB Strategy sets global targets of reducing tuberculosis incidence by 50% and mortality by 75% by 2025. We aimed to assess resource requirements and cost-effectiveness of strategies to achieve these targets in China, India, and South Africa.We examined intervention scenarios developed in consultation with country stakeholders, which scaled up existing interventions to high but feasible coverage by 2025. Nine independent modelling groups collaborated to estimate policy outcomes, and we estimated the cost of each scenario by synthesising service use estimates, empirical cost data, and expert opinion on implementation strategies. We estimated health effects (ie, disability-adjusted life-years averted) and resource implications for 2016-35, including patient-incurred costs. To assess resource requirements and cost-effectiveness, we compared scenarios with a base case representing continued current practice.Incremental tuberculosis service costs differed by scenario and country, and in some cases they more than doubled existing funding needs. In general, expansion of tuberculosis services substantially reduced patient-incurred costs and, in India and China, produced net cost savings for most interventions under a societal perspective. In all three countries, expansion of access to care produced substantial health gains. Compared with current practice and conventional cost-effectiveness thresholds, most intervention approaches seemed highly cost-effective.Expansion of tuberculosis services seems cost-effective for high-burden countries and could generate substantial health and economic benefits for patients, although substantial new funding would be required. Further work to determine the optimal intervention mix for each country is necessary.Bill & Melinda Gates Foundation.
View details for DOI 10.1016/S2214-109X(16)30265-0
View details for PubMedID 27720689
- Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models LANCET GLOBAL HEALTH 2016; 4 (11): E816-E826
Past and Future Performance: PEPFAR in the Landscape of Foreign Aid for Health
CURRENT HIV/AIDS REPORTS
2016; 13 (5): 256-262
This review traces the course of the US President's Emergency Plan for AIDS Relief (PEPFAR) as a foreign aid program. It illustrates how the epidemiologic and geopolitical environments of the early 2000s influenced PEPFAR's early directions and contributed to its successes. In addition to scaling up infrastructure and care delivery platforms, PEPFAR led to large increases in the number of people receiving antiretroviral therapy and reductions in mortality. These successes, in turn, have brought its principal challenges-its outsized budget, narrow focus, and problem of entitlement-into sharp relief. PEPFAR's recent evolution, then, has been in response to these challenges. This review suggests that PEPFAR's early formulation as an emergency response relieved it from a need to articulate clear goals, and that this freedom is now leading to new challenges as it struggles to identify priorities in the face of expectations to do more with a flat budget.
View details for DOI 10.1007/s11904-016-0326-8
View details for Web of Science ID 000384544000003
View details for PubMedID 27485837
Assessment of global guidelines for preventive chemotherapy against schistosomiasis and soil-transmitted helminthiasis: a cost-effectiveness modelling study
LANCET INFECTIOUS DISEASES
2016; 16 (9): 1065-1075
WHO guidelines recommend annual treatment for schistosomiasis or soil-transmitted helminthiasis when prevalence in school-aged children is at or above a threshold of 50% and 20%, respectively. Separate treatment guidelines are used for these two helminthiases, and integrated community-wide treatment is not recommended. We assessed the cost-effectiveness of changing prevalence thresholds and treatment guidelines under an integrated delivery framework.We developed a dynamic, age-structured transmission and cost-effectiveness model that simulates integrated preventive chemotherapy programmes against schistosomiasis and soil-transmitted helminthiasis. We assessed a 5-year treatment programme with praziquantel (40 mg/kg per treatment) against schistosomiasis and albendazole (400 mg per treatment) against soil-transmitted helminthiasis at 75% coverage. We defined strategies as highly cost-effective if the incremental cost-effectiveness ratio was less than the World Bank classification for a low-income country (gross domestic product of US$1045 per capita). We calculated the prevalence thresholds for cost-effective preventive chemotherapy of various strategies, and estimated treatment needs for sub-Saharan Africa.Annual preventive chemotherapy against schistosomiasis was highly cost-effective in treatment of school-aged children at a prevalence threshold of 5% (95% uncertainty interval [UI] 1·7-5·2; current guidelines recommend treatment at 50% prevalence) and for community-wide treatment at a prevalence of 15% (7·3-18·5; current recommendation is unclear, some community treatment recommended at 50% prevalence). Annual preventive chemotherapy against soil-transmitted helminthiasis was highly cost-effective in treatment of school-aged children at a prevalence of 20% (95% UI 5·4-30·5; current guidelines recommend treatment at 20% prevalence) and the entire community at 60% (35·3-85·1; no guidelines available). When both helminthiases were co-endemic, prevalence thresholds using integrated delivery were lower. Using this revised treatment framework, we estimated that treatment needs would be six times higher than WHO guidelines for praziquantel and two times higher for albendazole. An additional 21·3% (95% Bayesian credible interval 20·4-22·2) of the population changed from receiving non-integrated treatment under WHO guidelines to integrated treatment (both praziquantel and albendazole). Country-specific economic differences resulted in heterogeneity around these prevalence thresholds.Annual preventive chemotherapy programmes against schistosomiasis and soil-transmitted helminthiasis are likely to be highly cost-effective at prevalences lower than WHO recommendations. These findings support substantial treatment scale-up, community-wide coverage, integrated treatment in co-endemic settings that yield substantial cost synergies, and country-specific treatment guidelines.Doris Duke Charitable Foundation, Mount Sinai Hospital-University Health Network AMO Innovation Fund, and Stanford University Medical Scholars Programme.
View details for DOI 10.1016/S1473-3099(16)30073-1
View details for Web of Science ID 000381655200036
View details for PubMedID 27286968
Antiretroviral Treatment Scale-Up and Tuberculosis Mortality in High TB/HIV Burden Countries: An Econometric Analysis
2016; 11 (8)
Antiretroviral therapy (ART) reduces mortality in patients with active tuberculosis (TB), but the population-level relationship between ART coverage and TB mortality is untested. We estimated the reduction in population-level TB mortality that can be attributed to increasing ART coverage across 41 high HIV-TB burden countries.We compiled TB mortality trends between 1996 and 2011 from two sources: (1) national program-reported TB death notifications, adjusted for annual TB case detection rates, and (2) WHO TB mortality estimates. National coverage with ART, as proportion of HIV-infected people in need, was obtained from UNAIDS. We applied panel linear regressions controlling for HIV prevalence (5-year lagged), coverage of TB interventions (estimated by WHO and UNAIDS), gross domestic product per capita, health spending from domestic sources, urbanization, and country fixed effects.Models suggest that that increasing ART coverage was followed by reduced TB mortality, across multiple specifications. For death notifications at 2 to 5 years following a given ART scale-up, a 1% increase in ART coverage predicted 0.95% faster mortality rate decline (p = 0.002); resulting in 27% fewer TB deaths in 2011 alone than would have occurred without ART. Based on WHO death estimates, a 1% increase in ART predicted a 1.0% reduced TB death rate (p<0.001), and 31% fewer deaths in 2011. TB mortality was higher at higher HIV prevalence (p<0.001), but not related to coverage of isoniazid preventive therapy, cotrimoxazole preventive therapy, or other covariates.This econometric analysis supports a substantial impact of ART on population-level TB mortality realized already within the first decade of ART scale-up, that is apparent despite variable-quality mortality data.
View details for DOI 10.1371/journal.pone.0160481
View details for Web of Science ID 000381577000021
View details for PubMedID 27536864
Evaluation of a Urine Pooling Strategy for the Rapid and Cost-Efficient Prevalence Classification of Schistosomiasis.
PLoS neglected tropical diseases
2016; 10 (8)
A key epidemiologic feature of schistosomiasis is its focal distribution, which has important implications for the spatial targeting of preventive chemotherapy programs. We evaluated the diagnostic accuracy of a urine pooling strategy using a point-of-care circulating cathodic antigen (POC-CCA) cassette test for detection of Schistosoma mansoni, and employed simulation modeling to test the classification accuracy and efficiency of this strategy in determining where preventive chemotherapy is needed in low-endemicity settings.We performed a cross-sectional study involving 114 children aged 6-15 years in six neighborhoods in Azaguié Ahoua, south Côte d'Ivoire to characterize the sensitivity and specificity of the POC-CCA cassette test with urine samples that were tested individually and in pools of 4, 8, and 12. We used a Bayesian latent class model to estimate test characteristics for individual POC-CCA and quadruplicate Kato-Katz thick smears on stool samples. We then developed a microsimulation model and used lot quality assurance sampling to test the performance, number of tests, and total cost per school for each pooled testing strategy to predict the binary need for school-based preventive chemotherapy using a 10% prevalence threshold for treatment.The sensitivity of the urine pooling strategy for S. mansoni diagnosis using pool sizes of 4, 8, and 12 was 85.9%, 79.5%, and 65.4%, respectively, when POC-CCA trace results were considered positive, and 61.5%, 47.4%, and 30.8% when POC-CCA trace results were considered negative. The modeled specificity ranged from 94.0-97.7% for the urine pooling strategies (when POC-CCA trace results were considered negative). The urine pooling strategy, regardless of the pool size, gave comparable and often superior classification performance to stool microscopy for the same number of tests. The urine pooling strategy with a pool size of 4 reduced the number of tests and total cost compared to classical stool microscopy.This study introduces a method for rapid and efficient S. mansoni prevalence estimation through examining pooled urine samples with POC-CCA as an alternative to widely used stool microscopy.
View details for DOI 10.1371/journal.pntd.0004894
View details for PubMedID 27504954
View details for PubMedCentralID PMC4978437
- Cost-Effectiveness of HIV Preexposure Prophylaxis for People Who Inject Drugs in the United States ANNALS OF INTERNAL MEDICINE 2016; 165 (1): 10-?
- Sustainable HIV treatment in Africa through viral-load-informed differentiated care NATURE 2015; 528 (7580): S68-S76
- Health and Economic Implications of National Treatment Coverage for Cardiovascular Disease in India Cost-Effectiveness Analysis CIRCULATION-CARDIOVASCULAR QUALITY AND OUTCOMES 2015; 8 (6): 541-551
- Reply to Young et al. Clinical infectious diseases 2015; 61 (7): 1207-1208
Cost-effectiveness of improvements in diagnosis and treatment accessibility for tuberculosis control in India.
international journal of tuberculosis and lung disease
2015; 19 (9): 1115-?
Inaccurate diagnosis and inaccessibility of care undercut the effectiveness of high-quality anti-tuberculosis treatment and select for resistance. Rapid diagnostic systems, such as Xpert(®) MTB/RIF for tuberculosis (TB) diagnosis and drug susceptibility testing (DST), and programs that provide high-quality DOTS anti-tuberculosis treatment to patients in the unregulated private sector (public-private mix [PPM]), may help address these challenges, albeit at increased cost.We extended a microsimulation model of TB in India calibrated to demographic, epidemiologic, and care trends to evaluate 1) replacing DST with Xpert; 2) replacing microscopy and culture with Xpert to diagnose multidrug-resistant TB (MDR-TB) and non-MDR-TB; 3) implementing nationwide PPM; and combinations of (3) with (1) or (2).PPM (assuming costs of $38/person) and Xpert improved health and increase costs relative to the status quo. PPM alone or with Xpert cost <1 gross domestic product/capita per quality-adjusted life-year gained relative to the next best intervention, and dominated Xpert interventions excluding PPM.While both PPM and Xpert are promising tools for combatting TB in India, PPM should be prioritized over Xpert, as private sector engagement is more cost-effective than Xpert alone and, if sufficient resources are available, would substantially increase the value of Xpert if both interventions are implemented together.
View details for DOI 10.5588/ijtld.15.0158
View details for PubMedID 26260835
- Cost-effectiveness of improvements in diagnosis and treatment accessibility for tuberculosis control in India INTERNATIONAL JOURNAL OF TUBERCULOSIS AND LUNG DISEASE 2015; 19 (9): 1115-1124
Risk of Cardiovascular Events Associated With Current Exposure to HIV Antiretroviral Therapies in a US Veteran Population.
Clinical infectious diseases
2015; 61 (3): 445-452
To characterize the association of antiretroviral drug combinations on risk of cardiovascular events. Certain antiretroviral medications for human immunodeficiency virus (HIV) have been implicated in increasing risk of cardiovascular disease. However, antiretroviral drugs are typically prescribed in combination. We characterized the association of current exposure to antiretroviral drug combinations on risk of cardiovascular events including myocardial infarction, stroke, percutaneous coronary intervention, and coronary artery bypass surgery. We used the Veterans Health Administration Clinical Case Registry to analyze data from 24 510 patients infected with HIV from January 1996 through December 2009. We assessed the association of current exposure to 15 antiretroviral drugs and 23 prespecified combinations of agents on the risk of cardiovascular event by using marginal structural models and Cox models extended to accommodate time-dependent variables. Over 164 059 person-years of follow-up, 934 patients had a cardiovascular event. Current exposure to abacavir, efavirenz, lamivudine, and zidovudine was significantly associated with increased risk of cardiovascular event, with odds ratios ranging from 1.40 to 1.53. Five combinations were significantly associated with increased risk of cardiovascular event, all of which involved lamivudine. One of these-efavirenz, lamivudine, and zidovudine-was the second most commonly used combination and was associated with a risk of cardiovascular event that is 1.60 times that of patients not currently exposed to the combination (odds ratio = 1.60, 95% confidence interval, 1.25-2.04). In the VA cohort, exposure to both individual drugs and drug combinations was associated with modestly increased risk of a cardiovascular event.
View details for DOI 10.1093/cid/civ316
View details for PubMedID 25908684
International aid and natural disasters: a pre- and post-earthquake longitudinal study of the healthcare infrastructure in leogane, haiti.
American journal of tropical medicine and hygiene
2015; 92 (2): 448-453
The reconstruction of healthcare systems in developing countries after natural disasters is poorly understood. Using data collected before and after the 2010 Haiti earthquake, we detail the response of aid agencies and their interaction with local healthcare providers in Leogane, the city closest to the epicenter. We find that the period after the earthquake was associated with an increase in the total number of healthcare facilities, inpatient beds, and surgical facilities and that international aid has been a driving force behind this recovery. Aid has funded 12 of 13 new healthcare facilities that have opened since the earthquake as well as the reconstruction of 7 of 8 healthcare facilities that have been rebuilt. Despite increases in free, aid-financed healthcare, private Haitian healthcare facilities have remained at a constant number. The planned phase-out of several aid-financed facilities, however, will leave Leogane with fewer inpatient beds and healthcare services compared with the pre-earthquake period.
View details for DOI 10.4269/ajtmh.14-0379
View details for PubMedID 25510716
View details for PubMedCentralID PMC4347354
- Mortality changes after grants from the Global Fund to Fight AIDS, tuberculosis and malaria: an econometric analysis from 1995 to 2010. BMC public health 2015; 15 (1): 977-?
- Comparing Decisions for Malaria Testing and Presumptive Treatment: A Net Health Benefit Analysis MEDICAL DECISION MAKING 2014; 34 (8): 996-1005
- Government health insurance for people below poverty line in India: quasi-experimental evaluation of insurance and health outcomes BMJ-BRITISH MEDICAL JOURNAL 2014; 349
- Government health insurance for people below poverty line in India: quasi-experimental evaluation of insurance and health outcomes BMJ-BRITISH MEDICAL JOURNAL 2014; 349
- Population-level associations between antiretroviral therapy scale-up and all-cause mortality in South Africa INTERNATIONAL JOURNAL OF STD & AIDS 2014; 25 (9): 636-642
The relationship of health aid to population health improvements.
JAMA internal medicine
2014; 174 (6): 881-887
International aid to the health sector is an important component of all health spending in many developing countries. The relationship between health aid and changes in population health among aid recipients remains unknown.To quantify the relationship between health aid and changes in life expectancy and mortality in children younger than 5 years (under-5 mortality) among aid recipient nations.Cross-country panel data analysis of the relationship between measures of health aid, life expectancy, and under-5 mortality. Using difference models for longitudinal data with fixed effects for countries and years, we estimated the unique relationship between health aid and changes in life expectancy and under-5 mortality, controlling for gross domestic product per capita, urbanization, and total fertility rate.A total of 140 aid-recipient countries between 1974 and 2010.Annual amount of development assistance directed to the health sector in constant 2010 US dollars.Improvements in under-5 mortality and life expectancy in the period following aid receipt.Between 1974 and 2010, each 1% increase in health aid was associated with 0.24 months greater increase in life expectancy (95% CI, 0.02-0.46) (P = .03) and a 0.14 per 1000 live births faster decline in the probability of under-5 deaths per 1000 live births (95% CI, 0.02-0.26) (P = .02). The association between health aid and health improvements has strengthened over time, with the closest association occurring between 2000 and 2010. Health improvements associated with health aid are measurable for 3 to 5 years after aid disbursement. These findings imply that an increase of $1 billion in health aid could be associated with 364,800 fewer under-5 deaths (95% CI, 98,400-630,000).International aid to the health sector is related to increasing life expectancy and declining under-5 mortality. The benefits from aid appear to last for several years and have been greatest between 2000 and 2010, possibly because of improving health technologies or effective targeting of aid.
View details for DOI 10.1001/jamainternmed.2014.292
View details for PubMedID 24756557
- The relationship of health aid to population health improvements. JAMA internal medicine 2014; 174 (6): 881-887
Is Health Aid Reaching the Poor? Analysis of Household Data from Aid Recipient Countries
2014; 9 (1)
To determine the extent to which the narrowing of child mortality across wealth gradients has been related to foreign aid to the health sector in low- and middle-income countries.Mortality and wealth data on 989,901 under-5 children from 957,674 households in 49 aid recipient countries in Africa, Asia, South America, and the Caribbean between 1993 and 2012 were used in the analysis. Declines in under-5 mortality in the four poorest wealth quantiles were compared to the decline among the wealthiest at varying levels of health aid per capita using fixed effects multivariable regression models and controlling for maternal education, urbanization, and domestic spending on health among recipient countries.Each additional dollar in total health aid per capita was associated with 5.7 fewer deaths per 10,000 child-years among children in the poorest relative to the wealthiest households (p<0.001). This was also true when measured in percent declines (1.90% faster decline in under-5 mortality among the poorest compared with the wealthiest with each dollar in total health aid, p = 0.008). The association was stronger when using health aid specifically for malaria than total health aid, 12.60% faster decline among the poorest compared with the wealthiest with each dollar in malaria aid, p = 0.001.Foreign aid to the health sector is preferentially related to reductions in under-5 mortality among the poorest compared with the wealthiest. Health aid addressing malaria, which imposes a disproportionate burden among the poor, may explain the observed effect.
View details for DOI 10.1371/journal.pone.0084025
View details for Web of Science ID 000329460800027
View details for PubMedID 24404148
Disease control implications of India's changing multi-drug resistant tuberculosis epidemic.
2014; 9 (3)
Multi-drug resistant tuberculosis (MDR TB) is a major health challenge in India that is gaining increasing public attention, but the implications of India's evolving MDR TB epidemic are poorly understood. As India's MDR TB epidemic is transitioning from a treatment-generated to transmission-generated epidemic, we sought to evaluate the potential effectiveness of the following two disease control strategies on reducing the prevalence of MDR TB: a) improving treatment of non-MDR TB; b) shortening the infectious period between the activation of MDR TB and initiation of effective MDR treatment.We developed a dynamic transmission microsimulation model of TB in India. The model followed individuals by age, sex, TB status, drug resistance status, and treatment status and was calibrated to Indian demographic and epidemiologic TB time trends. The main effectiveness measure was reduction in the average prevalence reduction of MDR TB over the ten years after control strategy implementation. We find that improving non-MDR cure rates to avoid generating new MDR cases will provide substantial non-MDR TB benefits but will become less effective in reducing MDR TB prevalence over time because more cases will occur from direct transmission - by 2015, the model estimates 42% of new MDR cases are transmission-generated and this proportion continues to rise over time, assuming equal transmissibility of MDR and drug-susceptible TB. Strategies that disrupt MDR transmission by shortening the time between MDR activation and treatment are projected to provide greater reductions in MDR prevalence compared with improving non-MDR treatment quality: implementing MDR diagnostic improvements in 2017 is expected to reduce MDR prevalence by 39%, compared with 11% reduction from improving non-MDR treatment quality.As transmission-generated MDR TB becomes a larger driver of the MDR TB epidemic in India, rapid and accurate MDR TB diagnosis and treatment will become increasingly effective in reducing MDR TB cases compared to non-MDR TB treatment improvements.
View details for DOI 10.1371/journal.pone.0089822
View details for PubMedID 24608234
- Comparative effectiveness and cost-effectiveness of antiretroviral therapy and pre-exposure prophylaxis for HIV prevention in South Africa. BMC medicine 2014; 12: 46-?
- Disease Control Implications of India's Changing Multi-Drug Resistant Tuberculosis Epidemic. PloS one 2014; 9 (3)
Comparative effectiveness and cost-effectiveness of antiretroviral therapy and pre-exposure prophylaxis for HIV prevention in South Africa.
2014; 12: 46-?
Antiretroviral therapy (ART) and oral pre-exposure prophylaxis (PrEP) are effective in reducing HIV transmission in heterosexual adults. The epidemiologic impact and cost-effectiveness of combined prevention approaches in resource-limited settings remain unclear.We develop a dynamic mathematical model of the HIV epidemic in South Africa's adult population. We assume ART reduces HIV transmission by 95% and PrEP by 60%. We model two ART strategies: scaling up access for those with CD4 counts ≤ 350 cells/μL (Guidelines) and for all identified HIV-infected individuals (Universal). PrEP strategies include use in the general population (General) and in high-risk individuals (Focused). We consider strategies where ART, PrEP, or both are scaled up to 100% of remaining eligible individuals yearly. We measure infections averted, quality-adjusted life-years (QALYs) gained and incremental cost-effectiveness ratios over 20 years.Scaling up ART to 50% of eligible individuals averts 1,513,000 infections over 20 years (Guidelines) and 3,591,000 infections (Universal). Universal ART is the most cost-effective strategy at any scale ($160-$220/QALY versus comparable scale Guidelines ART expansion). General PrEP is costly and provides limited benefits beyond ART scale-up ($7,680/QALY to add 100% PrEP to 50% Universal ART). Cost-effectiveness of General PrEP becomes less favorable when ART is widely given ($12,640/QALY gained when added to 100% Universal ART). If feasible, Focused PrEP is cost saving or highly cost effective versus status quo and when added to ART strategies.Expanded ART coverage to individuals in early disease stages may be more cost-effective than current guidelines. PrEP can be cost-saving if delivered to individuals at increased risk of infection.
View details for DOI 10.1186/1741-7015-12-46
View details for PubMedID 24629217
- Risk of Cardiovascular Disease from Antiretroviral Therapy for HIV: A Systematic Review PLOS ONE 2013; 8 (3)
Risk of cardiovascular disease from antiretroviral therapy for HIV: a systematic review.
2013; 8 (3)
Recent studies suggest certain antiretroviral therapy (ART) drugs are associated with increases in cardiovascular disease.We performed a systematic review and meta-analysis to summarize the available evidence, with the goal of elucidating whether specific ART drugs are associated with an increased risk of myocardial infarction (MI).We searched Medline, Web of Science, the Cochrane Library, and abstract archives from the Conference on Retroviruses and Opportunistic Infections and International AIDS Society up to June 2011 to identify published articles and abstracts.Eligible studies were comparative and included MI, strokes, or other cardiovascular events as outcomes.Eligibility screening, data extraction, and quality assessment were performed independently by two investigators.Random effects methods and Fisher's combined probability test were used to summarize evidence.Twenty-seven studies met inclusion criteria, with 8 contributing to a formal meta-analysis. Findings based on two observational studies indicated an increase in risk of MI for patients recently exposed (usually defined as within last 6 months) to abacavir (RR 1.92, 95% CI 1.51-2.42) and protease inhibitors (PI) (RR 2.13, 95% CI 1.06-4.28). Our analysis also suggested an increased risk associated with each additional year of exposure to indinavir (RR 1.11, 95% CI 1.05-1.17) and lopinavir (RR 1.22, 95% CI 1.01-1.47). Our findings of increased cardiovascular risk from abacavir and PIs were in contrast to four published meta-analyses based on secondary analyses of randomized controlled trials, which found no increased risk from cardiovascular disease.Although observational studies implicated specific drugs, the evidence is mixed. Further, meta-analyses of randomized trials did not find increased risk from abacavir and PIs. Our findings that implicate specific ARTs in the observational setting provide sufficient evidence to warrant further investigation of this relationship in studies designed for that purpose.
View details for DOI 10.1371/journal.pone.0059551
View details for PubMedID 23555704
- Considerations in assessing the evidence and implications of aid displacement from the health sector. PLoS medicine 2013; 10 (1)
Performance of serum biomarkers for the early detection of invasive aspergillosis in febrile, neutropenic patients: a multi-state model.
2013; 8 (6)
The performance of serum biomarkers for the early detection of invasive aspergillosis expectedly depends on the timing of test results relative to the empirical administration of antifungal therapy during neutropenia, although a dynamic evaluation framework is lacking.We developed a multi-state model describing simultaneously the likelihood of empirical antifungal therapy and the risk of invasive aspergillosis during neutropenia. We evaluated whether the first positive test result with a biomarker is an independent predictor of invasive aspergillosis when both diagnostic information used to treat and risk factors of developing invasive aspergillosis are taken into account over time. We applied the multi-state model to a homogeneous cohort of 185 high-risk patients with acute myeloid leukemia. Patients were prospectively screened for galactomannan antigenemia twice a week for immediate treatment decision; 2,214 serum samples were collected on the same days and blindly assessed for (1->3)- β-D-glucan antigenemia and a quantitative PCR assay targeting a mitochondrial locus.The usual evaluation framework of biomarker performance was unable to distinguish clinical benefits of β-glucan or PCR assays. The multi-state model evidenced that the risk of invasive aspergillosis is a complex time function of neutropenia duration and risk management. The quantitative PCR assay accelerated the early detection of invasive aspergillosis (P = .010), independently of other diagnostic information used to treat, while β-glucan assay did not (P = .53).The performance of serum biomarkers for the early detection of invasive aspergillosis is better apprehended by the evaluation of time-varying predictors in a multi-state model. Our results provide strong rationale for prospective studies testing a preemptive antifungal therapy, guided by clinical, radiological, and bi-weekly blood screening with galactomannan antigenemia and a standardized quantitative PCR assay.
View details for DOI 10.1371/journal.pone.0065776
View details for PubMedID 23799048
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
Characteristics of US Emergency Departments That Offer Routine Human Immunodeficiency Virus Screening
ACADEMIC EMERGENCY MEDICINE
2012; 19 (8): 894-900
The association between emergency department (ED) characteristics, ED director's perceptions of preventive services, and the availability of human immunodeficiency virus (HIV) screening are unknown. The authors hypothesized that, after adjusting for ED operational and demographic characteristics, teaching hospital status would be associated with increased availability, and ED crowding and ED director agreement with barriers to screening would be associated with decreased availability.This was a secondary, cross-sectional analysis on previously collected data from 2008 to 2009 regarding availability of ED preventive services. Data were obtained from a random sample of 277 EDs in which ED directors provided information on ED characteristics and availability of HIV screening and rated five barriers to providing preventive services. The association between the availability of HIV screening and teaching hospital and crowding status, ED volume, urban-rural location, ownership, geographic region, patient demographics, state HIV testing consent laws, and ED director opinions on barriers to providing preventive services were determined in univariate analyses and a multivariate logistic regression model.Nineteen percent of the sampled EDs offer HIV screening. Teaching hospitals offer HIV screening more frequently than nonteaching hospitals (38% vs. 18%; p = 0.03), but after adjusting for other characteristics in a multivariate model, this association was not significant (relative risk ratio [RR] = 2.07, 95% confidence interval [CI] = 0.91 to 3.59). ED crowding also was not significantly associated with screening availability (RR = 0.66, 95% CI = 0.34 to 1.21). However, public ownership (RR = 2.13, 95% CI = 1.28 to 3.14), 24-hour social work (RR = 1.87, 95% CI = 1.02 to 2.99), uninsured population ≥35% (RR = 2.48, 95% CI = 1.39 to 3.69), increased local nonwhite minority population percentage (RR = 1.14 per 10%, 95% CI = 1.02 to 1.26), and state laws allowing opt-out consent for testing (RR = 1.76, 95% CI = 1.01 to 2.74) were associated with increased availability of screening in multivariable analysis. EDs whose directors were concerned about added costs were associated with decreased availability of screening (RR = 0.45, 95% CI = 0.23 to 0.85).After adjusting for other ED operational and demographic characteristics, ED crowding and teaching hospital affiliation were not independently associated with the availability of HIV screening. EDs whose directors were concerned about the cost of preventive services were less likely to provide routine HIV screening. Addressing ED director's concerns about the added costs of ED preventive services, increasing social work availability, and implementing testing laws consistent with Centers for Disease Control and Prevention (CDC) recommendations may facilitate increased adoption of ED HIV screening.
View details for DOI 10.1111/j.1553-2712.2012.01401.x
View details for Web of Science ID 000307772300001
View details for PubMedID 22849642
HIV and Africa's elderly: the problems and possibilities.
2012; 26: S85-91
Demographic changes and the increasing availability and coverage of antiretroviral therapy imply that the burden of HIV is shifting to older age groups in sub-Saharan Africa. However, very little is known about the burden of disease and the unique considerations required to adequately treat and retain older Africans. In this review, we summarize the epidemiological data on HIV prevalence among older Africans, and review progress and barriers to accessing treatment and care. The unique clinical considerations distinguishing the management of older HIV-infected Africans are summarized, with a focus on cardiovascular disease, neuropsychiatric conditions, oncologic illness, and musculoskeletal morbidity. The review concludes by suggesting opportunities for improving our knowledge about and management of HIV among older Africans, including prevention opportunities and potential technologies, including a polypill for reducing comorbidity in this under-recognized highly vulnerable group.
View details for PubMedID 22781181
- HIV Treatment as Prevention: Systematic Comparison of Mathematical Models of the Potential Impact of Antiretroviral Therapy on HIV Incidence in South Africa PLOS MEDICINE 2012; 9 (7)
HIV treatment as prevention: systematic comparison of mathematical models of the potential impact of antiretroviral therapy on HIV incidence in South Africa.
2012; 9 (7)
Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART.Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results.Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact.
View details for DOI 10.1371/journal.pmed.1001245
View details for PubMedID 22802730
United States aid policy and induced abortion in Sub-Saharan Africa
BULLETIN OF THE WORLD HEALTH ORGANIZATION
2011; 89 (12): 873-880
To determine whether the Mexico City Policy, a United States government policy that prohibits funding to nongovernmental organizations performing or promoting abortion, was associated with the induced abortion rate in sub-Saharan Africa.Women in 20 African countries who had induced abortions between 1994 and 2008 were identified in Demographic and Health Surveys. A country's exposure to the Mexico City Policy was considered high (or low) if its per capita assistance from the United States for family planning and reproductive health was above (or below) the median among study countries before the policy's reinstatement in 2001. Using logistic regression and a difference-in-difference design, the authors estimated the differential change in the odds of having an induced abortion among women in high exposure countries relative to low exposure countries when the policy was reinstated.The study included 261,116 women aged 15 to 44 years. A comparison of 1994-2000 with 2001-2008 revealed an adjusted odds ratio for induced abortion of 2.55 for high-exposure countries versus low-exposure countries under the policy (95% confidence interval, CI: 1.76-3.71). There was a relative decline in the use of modern contraceptives in the high-exposure countries over the same time period.The induced abortion rate in sub-Saharan Africa rose in high-exposure countries relative to low-exposure countries when the Mexico City Policy was reintroduced. Reduced financial support for family planning may have led women to substitute abortion for contraception. Regardless of one's views about abortion, the findings may have important implications for public policies governing abortion.
View details for DOI 10.2471/BLT.11.091660
View details for Web of Science ID 000297885400020
View details for PubMedID 22271944
Health system determinants of infant, child and maternal mortality: A cross-sectional study of UN member countries
GLOBALIZATION AND HEALTH
Few studies have examined the link between health system strength and important public health outcomes across nations. We examined the association between health system indicators and mortality rates.We used mixed effects linear regression models to investigate the strength of association between outcome and explanatory variables, while accounting for geographic clustering of countries. We modelled infant mortality rate (IMR), child mortality rate (CMR), and maternal mortality rate (MMR) using 13 explanatory variables as outlined by the World Health Organization.Significant protective health system determinants related to IMR included higher physician density (adjusted rate ratio [aRR] 0.81; 95% Confidence Interval [CI] 0.71-0.91), higher sustainable access to water and sanitation (aRR 0.85; 95% CI 0.78-0.93), and having a less corrupt government (aRR 0.57; 95% CI 0.40-0.80). Out-of-pocket expenditures on health (aRR 1.29; 95% CI 1.03-1.62) were a risk factor. The same four variables were significantly related to CMR after controlling for other variables. Protective determinants of MMR included access to water and sanitation (aRR 0.88; 95% CI 0.82-0.94), having a less corrupt government (aRR 0.49; 95%; CI 0.36-0.66), and higher total expenditures on health per capita (aRR 0.84; 95% CI 0.77-0.92). Higher fertility rates (aRR 2.85; 95% CI: 2.02-4.00) were found to be a significant risk factor for MMR.Several key measures of a health system predict mortality in infants, children, and maternal mortality rates at the national level. Improving access to water and sanitation and reducing corruption within the health sector should become priorities.
View details for DOI 10.1186/1744-8603-7-42
View details for Web of Science ID 000298816800001
View details for PubMedID 22023970
Comparative Analysis of Old-Age Mortality Estimations in Africa
2011; 6 (10)
Survival to old ages is increasing in many African countries. While demographic tools for estimating mortality up to age 60 have improved greatly, mortality patterns above age 60 rely on models based on little or no demographic data. These estimates are important for social planning and demographic projections. We provide direct estimations of older-age mortality using survey data.Since 2005, nationally representative household surveys in ten sub-Saharan countries record counts of living and recently deceased household members: Burkina Faso, Côte d'Ivoire, Ethiopia, Namibia, Nigeria, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe. After accounting for age heaping using multiple imputation, we use this information to estimate probability of death in 5-year intervals ((5)q(x)). We then compare our (5)q(x) estimates to those provided by the World Health Organization (WHO) and the United Nations Population Division (UNPD) to estimate the differences in mortality estimates, especially among individuals older than 60 years old.We obtained information on 505,827 individuals (18.4% over age 60, 1.64% deceased). WHO and UNPD mortality models match our estimates closely up to age 60 (mean difference in probability of death -1.1%). However, mortality probabilities above age 60 are lower using our estimations than either WHO or UNPD. The mean difference between our sample and the WHO is 5.9% (95% CI 3.8-7.9%) and between our sample is UNPD is 13.5% (95% CI 11.6-15.5%). Regardless of the comparator, the difference in mortality estimations rises monotonically above age 60.Mortality estimations above age 60 in ten African countries exhibit large variations depending on the method of estimation. The observed patterns suggest the possibility that survival in some African countries among adults older than age 60 is better than previously thought. Improving the quality and coverage of vital information in developing countries will become increasingly important with future reductions in mortality.
View details for DOI 10.1371/journal.pone.0026607
View details for Web of Science ID 000296507500095
View details for PubMedID 22028921
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
The relation of price of antiretroviral drugs and foreign assistance with coverage of HIV treatment in Africa: retrospective study
BRITISH MEDICAL JOURNAL
To determine the association of reductions in price of antiretroviral drugs and foreign assistance for HIV with coverage of antiretroviral treatment.Retrospective study.Africa.13 African countries, 2003-8.A price index of first line antiretroviral therapy with data on foreign assistance for HIV was used to estimate the associations of prices and foreign assistance with antiretroviral coverage (percentage of people with advanced HIV infection receiving antiretroviral therapy), controlling for national public health spending, HIV prevalence, governance, and fixed effects for countries and years.Between 2003 and 2008 the annual price of first line antiretroviral therapy decreased from $1177 (£733; €844) to $96 and foreign assistance for HIV per capita increased from $0.4 to $13.8. At an annual price of $100, a $10 decrease was associated with a 0.16% adjusted increase in coverage (95% confidence interval 0.11% to 0.20%; 0.19% unadjusted, 0.14% to 0.24%). Each additional $1 per capita in foreign assistance for HIV was associated with a 1.0% adjusted increase in coverage (0.7% to 1.2%; 1.4% unadjusted, 1.1% to 1.6%). If the annual price of antiretroviral therapy stayed at $100, foreign assistance would need to quadruple to $64 per capita to be associated with universal coverage. Government effectiveness and national public health expenditures were also positively associated with increasing coverage.Reductions in price of antiretroviral drugs were important in broadening coverage of HIV treatment in Africa from 2003 to 2008, but their future role may be limited. Foreign assistance and national public health expenditures for HIV seem more important in expanding future coverage.
View details for DOI 10.1136/bmj.c6218
View details for Web of Science ID 000284586600002
View details for PubMedID 21088074
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
AIDS and declining support for dependent elderly people in Africa: retrospective analysis using demographic and health surveys
BRITISH MEDICAL JOURNAL
To determine the relation between the HIV/AIDS epidemic and support for dependent elderly people in Africa.Retrospective analysis using data from Demographic and Health Surveys.22 African countries between 1991 and 2006.123,176 individuals over the age of 60.We investigated how three measures of the living arrangements of older people have been affected by the HIV/AIDS epidemic: the number of older individuals living alone (that is, the number of unattended elderly people); the number of older individuals living with only dependent children under the age of 10 (that is, in missing generation households); and the number of adults age 18-59 (that is, prime age adults) per household where an older person lives.An increase in annual AIDS mortality of one death per 1000 people was associated with a 1.5% increase in the proportion of older individuals living alone (95% CI 1.2% to 1.9%) and a 0.4% increase in the number of older individuals living in missing generation households (95% CI 0.3% to 0.6%). Increases in AIDS mortality were also associated with fewer prime age adults in households with at least one older person and at least one prime age adult (P<0.001). These findings suggest that in our study countries, which encompass 70% of the sub-Saharan population, the HIV/AIDS epidemic could be responsible for 582,200-917,000 older individuals living alone without prime age adults and 141,000-323,100 older individuals being the sole caregivers for young children.Africa's HIV/AIDS epidemic might be responsible for a large number of older people losing their support and having to care for young children. This population has previously been under-recognised. Efforts to reduce HIV/AIDS deaths could have large "spillover" benefits for elderly people in Africa.
View details for DOI 10.1136/bmj.c2841
View details for Web of Science ID 000279051900002
View details for PubMedID 20554660
The relationship between HIV testing, stigma, and health service usage
AIDS CARE-PSYCHOLOGICAL AND SOCIO-MEDICAL ASPECTS OF AIDS/HIV
2010; 22 (3): 373-380
We explore whether HIV stigma is associated with seeking to conceal testing interest. We examine 86,899 outpatient visits in a 1993-1997 national survey and compare HIV testing to four non-stigmatized tests: spirometry, allergy testing, mammography, and colonoscopy. We explore whether people testing for HIV, compared to people receiving control services, listed reasons for visit (RFV) less related to the test performed, listed their interest in testing more frequently as a non-primary RFV, and received more services unrelated to testing. A total of 48.7% of people tested for HIV listed a reason unrelated to testing as their primary RFV (spirometry: 8.9%; allergy testing: 29.3%), and 69.9% of people asking to test requested HIV testing as a secondary RFV (spirometry: 52%; allergy testing: 0%). People who tested for HIV received more services (M=1.83 additional services) than non-testers (M=0.95) on an index of seven services. We did not find this association for spirometry, allergy testing, colonoscopy, or mammography. We interpret these results to indicate that stigma may have behavioral correlates and that people may attempt to avoid HIV stigma by seeking a psychological cover for HIV testing. To our knowledge, this is the first study to attempt to use observational data on health service usage for assessing stigma and people's attempts to deal with HIV testing stigma.
View details for DOI 10.1080/09540120903193666
View details for Web of Science ID 000277313600013
View details for PubMedID 20390518
- Cost-effectiveness of antiretroviral regimens in the World Health Organization's treatment guidelines: a South African analysis AIDS 2010
Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: Effects on level of residual viremia and quality of life
JOURNAL OF CLINICAL VIROLOGY
2009; 46 (4): 305-308
Raltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.To characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.In patients with viral load <50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load >1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.Fourteen patients with a median CD4+ T-cell count of 420 cells/microL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.A switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.
View details for DOI 10.1016/j.jcv.2009.09.025
View details for Web of Science ID 000272460900002
View details for PubMedID 19819183
Expanding Antiretroviral Options in Resource-Limited Settings-A Cost-Effectiveness Analysis
JAIDS-JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES
2009; 52 (1): 106-113
Current World Health Organization (WHO) guidelines for treatment of HIV in resource-limited settings call for 2 antiretroviral regimens. The effectiveness and cost-effectiveness of increasing the number of antiretroviral regimens is unknown.Using a simulation model, we compared the survival and costs of current WHO regimens with two 3-regimen strategies: an initial regimen of 3 nucleoside reverse transcriptase inhibitors followed by the WHO regimens and the WHO regimens followed by a regimen with a second-generation boosted protease inhibitor (2bPI). We evaluated monitoring with CD4 counts only and with both CD4 counts and viral load. We used cost and effectiveness data from Cape Town and tested all assumptions in sensitivity analyses.Over the lifetime of the cohort, 25.6% of individuals failed both WHO regimens by virologic criteria. However, when patients were monitored using CD4 counts alone, only 6.5% were prescribed additional highly active antiretroviral therapy due to missed and delayed detection of failure. The life expectancy gain for individuals who took a 2bPI was 6.7-8.9 months, depending on the monitoring strategy. When CD4 alone was available, adding a regimen with a 2bPI was associated with an incremental cost-effectiveness ratio of $2581 per year of life gained, and when viral load was available, the ratio was $6519 per year of life gained. Strategies with triple-nucleoside reverse transcriptase inhibitor regimens in initial therapy were dominated. Results were sensitive to the price of 2bPIs.About 1 in 4 individuals who start highly active antiretroviral therapy in sub-Saharan Africa will fail currently recommended regimens. At current prices, adding a regimen with a 2bPI is cost effective for South Africa and other middle-income countries by WHO standards.
View details for Web of Science ID 000269373400015
View details for PubMedID 19448557
The President's Emergency Plan for AIDS Relief in Africa: An Evaluation of Outcomes
ANNALS OF INTERNAL MEDICINE
2009; 150 (10): 688-U5
Since 2003, the President's Emergency Plan for AIDS Relief (PEPFAR) has been the most ambitious initiative to address the global HIV epidemic. However, the effect of PEPFAR on HIV-related outcomes is unknown.To assess the effect of PEPFAR on HIV-related deaths, the number of people living with HIV, and HIV prevalence in sub-Saharan Africa.Comparison of trends before and after the initiation of PEPFAR's activities.12 African focus countries and 29 control countries with a generalized HIV epidemic from 1997 to 2007 (451 country-year observations).A 5-year, $15 billion program for HIV treatment, prevention, and care that started in late 2003.HIV-related deaths, the number of people living with HIV, and HIV prevalence.Between 2004 and 2007, the difference in the annual change in the number of HIV-related deaths was 10.5% lower in the focus countries than in the control countries (P = 0.001). The difference in trends between the groups before 2003 was not significant. The annual growth in the number of people living with HIV was 3.7% slower in the focus countries than in the control countries from 1997 to 2002 (P = 0.05), but during PEPFAR's activities, the difference was no longer significant. The difference in the change in HIV prevalence did not significantly differ throughout the study period. These estimates were stable after sensitivity analysis.The selection of the focus countries was not random, which limits the generalizability of the results.After 4 years of PEPFAR activity, HIV-related deaths decreased in sub-Saharan African focus countries compared with control countries, but trends in adult prevalence did not differ. Assessment of epidemiologic effectiveness should be part of PEPFAR's evaluation programs.Agency for Healthcare Research and Quality.
View details for Web of Science ID 000266285300004
View details for PubMedID 19349625
Cost-effectiveness of Strategies for Monitoring the Response to Antiretroviral Therapy in Resource-Limited Settings Reply
ARCHIVES OF INTERNAL MEDICINE
2009; 169 (9): 904-905
View details for Web of Science ID 000265994000017
Cost-effectiveness of HIV monitoring strategies in resource-limited settings - A Southern African analysis
ARCHIVES OF INTERNAL MEDICINE
2008; 168 (17): 1910-1918
Although the number of infected persons receiving highly active antiretroviral therapy (HAART) in low- and middle-income countries has increased dramatically, optimal disease management is not well defined.We developed a model to compare the costs and benefits of 3 types of human immunodeficiency virus monitoring strategies: symptom-based strategies, CD4-based strategies, and CD4 counts plus viral load strategies for starting, switching, and stopping HAART. We used clinical and cost data from southern Africa and performed a cost-effectiveness analysis. All assumptions were tested in sensitivity analyses.Compared with the symptom-based approaches, monitoring CD4 counts every 6 months and starting treatment at a threshold of 200/muL was associated with a gain in life expectancy of 6.5 months (61.9 months vs 68.4 months) and a discounted lifetime cost savings of US $464 per person (US $4069 vs US $3605, discounted 2007 dollars). The CD4-based strategies in which treatment was started at the higher threshold of 350/microL provided an additional gain in life expectancy of 5.3 months at a cost-effectiveness of US $107 per life-year gained compared with a threshold of 200/microL. Monitoring viral load with CD4 was more expensive than monitoring CD4 counts alone, added 2.0 months of life, and had an incremental cost-effectiveness ratio of US $5414 per life-year gained relative to monitoring of CD4 counts. In sensitivity analyses, the cost savings from CD4 count monitoring compared with the symptom-based approaches was sensitive to cost of inpatient care, and the cost-effectiveness of viral load monitoring was influenced by the per test costs and rates of virologic failure.Use of CD4 monitoring and early initiation of HAART in southern Africa provides large health benefits relative to symptom-based approaches for HAART management. In southern African countries with relatively high costs of hospitalization, CD4 monitoring would likely reduce total health care expenditures. The cost-effectiveness of viral load monitoring depends on test prices and rates of virologic failure.
View details for Web of Science ID 000259393000011
View details for PubMedID 18809819
- Monitoring of antiretroviral therapy in low-resource settings LANCET 2008; 372 (9635): 288-289
Systematic review: The effects of growth hormone on athletic performance
ANNALS OF INTERNAL MEDICINE
2008; 148 (10): 747-U59
Human growth hormone is reportedly used to enhance athletic performance, although its safety and efficacy for this purpose are poorly understood.To evaluate evidence about the effects of growth hormone on athletic performance in physically fit, young individuals.MEDLINE, EMBASE, SPORTDiscus, and Cochrane Collaboration databases were searched for English-language studies published between January 1966 and October 2007.Randomized, controlled trials that compared growth hormone treatment with no growth hormone treatment in community-dwelling healthy participants between 13 and 45 years of age.2 authors independently reviewed articles and abstracted data.44 articles describing 27 study samples met inclusion criteria; 303 participants received growth hormone, representing 13.3 person-years of treatment. Participants were young (mean age, 27 years [SD, 3]), lean (mean body mass index, 24 kg/m2 [SD, 2]), and physically fit (mean maximum oxygen uptake, 51 mL/kg of body weight per minute [SD, 8]). Growth hormone dosage (mean, 36 microg/kg per day [SD, 21]) and treatment duration (mean, 20 days [SD, 18] for studies giving growth hormone for >1 day) varied. Lean body mass increased in growth hormone recipients compared with participants who did not receive growth hormone (increase, 2.1 kg [95% CI, 1.3 to 2.9 kg]), but strength and exercise capacity did not seem to improve. Lactate levels during exercise were statistically significantly higher in 2 of 3 studies that evaluated this outcome. Growth hormone-treated participants more frequently experienced soft tissue edema and fatigue than did those not treated with growth hormone.Few studies evaluated athletic performance. Growth hormone protocols in the studies may not reflect real-world doses and regimens.Claims that growth hormone enhances physical performance are not supported by the scientific literature. Although the limited available evidence suggests that growth hormone increases lean body mass, it may not improve strength; in addition, it may worsen exercise capacity and increase adverse events. More research is needed to conclusively determine the effects of growth hormone on athletic performance.
View details for Web of Science ID 000256372200004
View details for PubMedID 18347346
Complication rates on weekends and weekdays in US hospitals
AMERICAN JOURNAL OF MEDICINE
2007; 120 (5): 422-428
Recent studies and anecdotal evidence suggest that patient safety may be compromised on weekends. Our objective was to determine whether rates of complications in hospitals are higher on weekends than on weekdays.We examined records from 4,967,114 admissions to acute care hospitals in 3 states and analyzed complication rates using the Patient Safety Indicators. We selected 8 indicators that could be assigned to a single day: complications of anesthesia, retained foreign bodies, postoperative hemorrhage, accidental cuts and lacerations during procedures, birth trauma, obstetric trauma during vaginal deliveries with and without instrumentation, and obstetric trauma during cesarean delivery. Odds ratios (ORs) comparing weekends versus weekdays were adjusted for demographics, type of admission, and admission route. In a subgroup analysis of surgical complications, we restricted the population to patients who underwent cardiac or vascular procedures.Four of the 8 complications occurred more frequently on weekends: postoperative hemorrhage (OR 1.07, 95% confidence interval [CI], 1.01-1.14), newborn trauma (OR 1.06, 95% CI, 1.03-1.10), vaginal deliveries without instrumentation (OR 1.03, 95% CI, 1.02-1.04), and obstetric trauma during cesarean sections (OR 1.36, 95% CI, 1.29-1.44). Complications related to anesthesia occurred less frequently on weekends (OR 0.86). Among patients undergoing vascular procedures, surgical complications occurred more frequently on weekends (OR 1.46, 95% CI, 1.16-1.85).Rates of complications are marginally higher on weekends than on weekdays for some surgical and newborn complications, but more significantly for obstetric trauma and for surgical complications involving patients undergoing vascular procedures. Hospitals should work toward increasing the robustness of safeguards on weekends.
View details for DOI 10.1016/j.amjmed.2006.05.067
View details for Web of Science ID 000246061900012
View details for PubMedID 17466653
Hospital workload and adverse events
2007; 45 (5): 448-455
Hospitals are under pressure to increase revenue and lower costs, and at the same time, they face dramatic variation in clinical demand.: We sought to determine the relationship between peak hospital workload and rates of adverse events (AEs).A random sample of 24,676 adult patients discharged from the medical/surgical services at 4 US hospitals (2 urban and 2 suburban teaching hospitals) from October 2000 to September 2001 were screened using administrative data, leaving 6841 cases to be reviewed for the presence of AEs. Daily workload for each hospital was characterized by volume, throughput (admissions and discharges), intensity (aggregate DRG weight), and staffing (patient-to-nurse ratios). For volume, we calculated an "enhanced" occupancy rate that accounted for same-day bed occupancy by more than 1 patient. We used Poisson regressions to predict the likelihood of an AE, with control for workload and individual patient complexity, and the effects of clustering.One urban teaching hospital had enhanced occupancy rates more than 100% for much of the year. At that hospital, admissions and patients per nurse were significantly related to the likelihood of an AE (P < 0.05); occupancy rate, discharges, and DRG-weighted census were significant at P < 0.10. For example, a 0.1% increase in the patient-to-nurse ratio led to a 28% increase in the AE rate. Results at the other 3 hospitals varied and were mainly non significant.Hospitals that operate at or over capacity may experience heightened rates of patient safety events and might consider re-engineering the structures of care to respond better during periods of high stress.
View details for Web of Science ID 000246374200011
View details for PubMedID 17446831
Data withholding and the next generation of scientists: Results of a national survey
2006; 81 (2): 128-136
To provide the first national data on the nature, extent, and consequences of withholding among life science trainees.In 2003, the authors surveyed 1,077 second-year doctoral students and postdoctoral fellows in life sciences at 50 U.S. universities, with a comparison group of trainees in computer science and chemical engineering. The study variables examined trainees' exposure to and the consequences of data withholding.Two hundred forty-six trainees (23.0%) reported that they had asked for and been denied access to information, data, materials, or programming associated with published research and 221 (20.6%) to unpublished research. Eighty-five trainees (7.9%) reported that they had denied another academic scientist's request(s) related to their own published research. Five hundred thirty-three trainees (50.8%) reported that withholding had had a negative effect on the progress of their research, 508 (48.5%) on the rate of discovery in their lab/research group, 472 (45.0%) on the quality of their relationships with academic scientists, 346 (33.0%) on the quality of their education, and 299 (28.5%) on the level of communication in their lab/research group. Trainees denied access to research were significantly more likely to report that data withholding had had a negative effect on several aspects of the educational experience.Data withholding had demonstrated negative effects on trainees. The life sciences, more so than chemical engineering or computer science, will have to address this issue among its trainees. Failure to do so could result in delayed research, inefficient training, and a culture of withholding among future life scientists.
View details for Web of Science ID 000235023100005
View details for PubMedID 16436573
- Should US hospitals go 24/7? AMERICAN JOURNAL OF MEDICINE 2004; 117 (3): 202-203
Data-sharing and data-withholding in genetics and the life sciences: results of a national survey of technology transfer officers.
Journal of health care law & policy
2003; 6 (2): 241-255
View details for PubMedID 15017960