Dr. Chao is a board-certified general/trauma surgeon at Santa Clara Valley Medical Center, an Adjunct Professor of Surgery in the Department of Surgery/Division of General Surgery in the School of Medicine, and a Faculty Fellow at the Stanford Center for Innovation in Global Health. She is the co-director of the undergraduate course HUMBIO 129S: Global Public Health and the medical school seminar SURG 236: Seminar in Global Surgery and Anesthesia, both Winter Quarter classes. She is also the associate director of Global Health: Beyond Diseases and International Organizations, a two-week intensive Spring Quarter course for Stanford residents and fellows.
Prior to her current roles, she served as a Paul Farmer Global Surgery Research Fellow with Harvard Medical School's Program in Global Surgery and Social Change. There, she conducted cost-effectiveness analyses and pursued expansion of surgical delivery for indigent populations through surgical workforce and infrastructure development internationally, working primarily in Liberia, Kenya, and Haiti. She completed the CTSA/Lucile Packard Innovation Fellowship at Stanford Biodesign, eventually becoming a co-founder of Zenflow, Inc., a venture-backed medical device company working in minimally-invasive therapy for prostate disease.
Dr. Chao holds dual Bachelor's degrees in Symbolic Systems and Psychology from Stanford University, as well as MD and MPH degrees from Mount Sinai School of Medicine, where she graduated with Alpha Omega Alpha honors. She completed General Surgery residency at the Massachusetts General Hospital in Boston.
Academic Staff - Hourly - CSL, Surgery - General Surgery
Tiffany E. CHAO, Nicholas R. DAMIANO, Shreya MEHTA, John P. WOOCK. "United States Patent US20150257908A1 Indwelling body lumen expander", Leland Stanford Junior University, Mar 14, 2014
Med Scholar Project Advisor
- Beyond outcomes: applying cost-effectiveness analysis to policy making. British journal of anaesthesia 2020
Catastrophic expenditures in California trauma patients after the Affordable Care Act: reduced financial risk and racial disparities.
American journal of surgery
BACKGROUND: Hospital charges due to major injury can result in high out-of-pocket expenses for patients. We analyzed the effect of the Affordable Care Act (ACA) on catastrophic health expenditures (CHE) among trauma patients.METHODS: We identified trauma patients aged 19-64 admitted to a safety-net Level 1 trauma center in California from 2007 to 2017. Out-of-pocket expenditures and income were calculated using hospital charges, insurance status, and ZIP code. CHE was defined using the World Health Organization definition of out-of-pocket spending exceeding 40% of inflation-adjusted income minus food and housing expenditures. Multivariable logistic regression was performed to assess odds of CHE post-ACA (2014-2017) vs. pre-ACA (2007-2013).RESULTS: Of 7519 trauma patients, 20.6% experienced CHE, including 89.0% of uninsured patients. There was a 74% decrease in odds of CHE post-ACA (aOR: 0.26, 95% CI: 0.22-0.30), with greater decreases among Black (aOR: 0.09, 95% CI: 0.04-0.18) and Hispanic (aOR: 0.23, 95% CI: 0.19-0.29) patients.CONCLUSIONS: ACA implementation was associated with markedly decreased odds of catastrophic expenditures and decreased racial disparities in financial protection among trauma patients in our study.
View details for DOI 10.1016/j.amjsurg.2020.04.012
View details for PubMedID 32354603
- Sex Disparities in the Global Burden of Surgical Disease. World journal of surgery 2020
Neurosurgical Randomized Trials in Low- and Middle-Income Countries.
BACKGROUND: The setting of a randomized trial can determine whether its findings are generalizable and can therefore apply to different settings. The contribution of low- and middle-income countries (LMICs) to neurosurgical randomized trials has not been systematically described before.OBJECTIVE: To perform a systematic analysis of design characteristics and methodology, funding source, and interventions studied between trials led by and/or conducted in high-income countries (HICs) vs LMICs.METHODS: From January 2003 to July 2016, English-language trials with >5 patients assessing any one neurosurgical procedure against another procedure, nonsurgical treatment, or no treatment were retrieved from MEDLINE, Scopus, and Cochrane Library. Income classification for each country was assessed using the World Bank Atlas method.RESULTS: A total of 73.3% of the 397 studies that met inclusion criteria were led by HICs, whereas 26.7% were led by LMICs. Of the 106 LMIC-led studies, 71 were led by China. If China is excluded, only 8.8% were led by LMICs. HIC-led trials enrolled a median of 92 patients vs a median of 65 patients in LMIC-led trials. HIC-led trials enrolled from 7.6 sites vs 1.8 sites in LMIC-led studies. Over half of LMIC-led trials were institutionally funded (54.7%). The majority of both HIC- and LMIC-led trials evaluated spinal neurosurgery, 68% and 71.7%, respectively.CONCLUSION: We have established that there is a substantial disparity between HICs and LMICs in the number of published neurosurgical trials. A concerted effort to invest in research capacity building in LMICs is an essential step towards ensuring context- and resource-specific high-quality evidence is generated.
View details for DOI 10.1093/neuros/nyaa049
View details for PubMedID 32171011
Use of vital signs in Predicting surgical intervention in a South African population: A cross-sectional study.
International journal of surgery (London, England)
While vital signs are widely obtained for trauma patients around the world, the association of these signs with need for surgical intervention has yet to be defined. Early detection of preventable outcomes is essential to timely intervention and reduction of morbidity and mortality.The aim of this study was to determine the association of vital signs and surgical intervention in a population of patients in South Africa.This retrospective cohort included 8722 trauma patients admitted at **** Hospital in Pietermaritzburg, South Africa over a five-year period December 2012-April 2018. Exclusion criteria included missing key data points. Variables for analysis included sex, mechanism of injury, admission Glasgow Coma Scale (GCS), systolic blood pressure, diastolic blood pressure, temperature, heart rate, and respiratory rate. Surgical intervention was defined by the need for treatment requiring time in the operating room. Data were analyzed using a univariate and multivariate logistic regression to determine an association between admission vital signs and surgical intervention and compared to the association of the Revised Trauma Score to surgical intervention.Of the 8722 trauma patient records available, exclusion of patients with incomplete data resulted in 7857 patient records available for analysis. Two thousand two hundred and ninety-six (29.2%) patients required surgical intervention in the operating room. Multivariate analysis revealed that male sex [odds ratio (OR) 1.25, 95% confidence interval (CI) 1.06-1.48], stab wound (OR 3.42, CI 2.99-3.09), gunshot wound (OR 4.27, CI 3.58-5.09), systolic hypotension (OR 1.81, CI 1.32- 2.48), hypothermia(OR 1.77, CI 1.34-2.34), tachycardia (OR 1.84, CI 1.61- 2.10), and tachypnea (OR 1.26, CI 1.08-1.45) as factors ssociated withan increased likelihood of surgical intervention.In this cohort of patients, the need for surgical intervention was best predicted by penetrating mechanisms of injury, tachycardia, and systolic hypotension. These data show that rapid and focused patient assessments should be used to triage patients foremergency surgery to avoid delays at any stage.
View details for DOI 10.1016/j.ijsu.2020.05.013
View details for PubMedID 32413507
Operative Burden in Conflict vs Nonconflict Settings: Experience of Medecins Sans Frontieres
ELSEVIER SCIENCE INC. 2019: S136
View details for Web of Science ID 000492740900249
- Impact of Affordable Care Act Implementation on Catastrophic Health Expenditures among Trauma Patients ELSEVIER SCIENCE INC. 2018: S148–S149
Cost-Effectiveness in Global Surgery: Pearls, Pitfalls, and a Checklist
WORLD JOURNAL OF SURGERY
2017; 41 (6): 1401–13
Cost-effectiveness analysis can be a powerful policy-making tool. In the two decades since the first cost-effectiveness analyses in global surgery, the methodology has established the cost-effectiveness of many types of surgery in low- and middle-income countries (LMICs). However, with the crescendo of cost-effectiveness analyses in global surgery has come vast disparities in methodology, with only 15% of studies adhering to published guidelines. This has led to results that have varied up to 150-fold.The theoretical basis, common pitfalls, and guidelines-based recommendations for cost-effectiveness analyses are reviewed, and a checklist to be used for cost-effectiveness analyses in global surgery is created.Common pitfalls in global surgery cost-effectiveness analyses fall into five categories: the analytic perspective, cost measurement, effectiveness measurement, probability estimation, valuation of the counterfactual, and heterogeneity and uncertainty. These are reviewed in turn, and a checklist to avoid these pitfalls is developed.Cost-effectiveness analyses, when done rigorously, can be very useful for the development of efficient surgical systems in LMICs. This review highlights the common pitfalls in these analyses and methods to avoid these pitfalls.
View details for DOI 10.1007/s00268-017-3875-0
View details for Web of Science ID 000400972800001
View details for PubMedID 28105528
A geospatial evaluation of timely access to surgical care in seven countries
BULLETIN OF THE WORLD HEALTH ORGANIZATION
2017; 95 (6): 437–44
To assess the consistent availability of basic surgical resources at selected facilities in seven countries.In 2010-2014, we used a situational analysis tool to collect data at district and regional hospitals in Bangladesh (n = 14), the Plurinational State of Bolivia (n = 18), Ethiopia (n = 19), Guatemala (n = 20), the Lao People's Democratic Republic (n = 12), Liberia (n = 12) and Rwanda (n = 25). Hospital sites were selected by pragmatic sampling. Data were geocoded and then analysed using an online data visualization platform. Each hospital's catchment population was defined as the people who could reach the hospital via a vehicle trip of no more than two hours. A hospital was only considered to show consistent availability of basic surgical resources if clean water, electricity, essential medications including intravenous fluids and at least one anaesthetic, analgesic and antibiotic, a functional pulse oximeter, a functional sterilizer, oxygen and providers accredited to perform surgery and anaesthesia were always available.Only 41 (34.2%) of the 120 study hospitals met the criteria for the provision of consistent basic surgical services. The combined catchments of the study hospitals in each study country varied between 3.3 million people in Liberia and 151.3 million people in Bangladesh. However, the combined catchments of the study hospitals in each study country that met the criteria for the provision of consistent basic surgical services were substantially smaller and varied between 1.3 million in Liberia and 79.2 million in Bangladesh.Many study facilities were deficient in the basic infrastructure necessary for providing basic surgical care on a consistent basis.
View details for PubMedID 28603310
View details for PubMedCentralID PMC5463808
- Staged Particle and Ethanol Embolotherapy of a Symptomatic Pancreatic Arteriovenous Malformation JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY 2016; 27 (11): 1734–35
- A Multinational Evaluation of Timely Access to Basic Surgical Services Using Geospatial Analyses ELSEVIER SCIENCE INC. 2016: E118
Size and distribution of the global volume of surgery in 2012
BULLETIN OF THE WORLD HEALTH ORGANIZATION
2016; 94 (3): 201-209
To estimate global surgical volume in 2012 and compare it with estimates from 2004.For the 194 Member States of the World Health Organization, we searched PubMed for studies and contacted key informants for reports on surgical volumes between 2005 and 2012. We obtained data on population and total health expenditure per capita for 2012 and categorized Member States as very-low, low, middle and high expenditure. Data on caesarean delivery were obtained from validated statistical reports. For Member States without recorded surgical data, we estimated volumes by multiple imputation using data on total health expenditure. We estimated caesarean deliveries as a proportion of all surgery.We identified 66 Member States reporting surgical data. We estimated that 312.9 million operations (95% confidence interval, CI: 266.2-359.5) took place in 2012, an increase from the 2004 estimate of 226.4 million operations. Only 6.3% (95% CI: 1.7-22.9) and 23.1% (95% CI: 14.8-36.7) of operations took place in very-low- and low-expenditure Member States representing 36.8% (2573 million people) and 34.2% (2393 million people) of the global population of 7001 million people, respectively. Caesarean deliveries comprised 29.6% (5.8/19.6 million operations; 95% CI: 9.7-91.7) of the total surgical volume in very-low-expenditure Member States, but only 2.7% (5.1/187.0 million operations; 95% CI: 2.2-3.4) in high-expenditure Member States.Surgical volume is large and growing, with caesarean delivery comprising nearly a third of operations in most resource-poor settings. Nonetheless, there remains disparity in the provision of surgical services globally.
View details for DOI 10.2471/BLT.15.159293
View details for Web of Science ID 000372774200017
View details for PubMedCentralID PMC4773932
Systematic review of laparoscopic surgery in low- and middle-income countries: benefits, challenges, and strategies
SURGICAL ENDOSCOPY AND OTHER INTERVENTIONAL TECHNIQUES
2016; 30 (1): 1–10
Laparoscopy may prove feasible to address surgical needs in limited-resource settings. However, no aggregate data exist regarding the role of laparoscopy in low- and middle-income countries (LMICs). This study was designed to describe the issues facing laparoscopy in LMICs and to aggregate reported solutions.A search was conducted using Medline, African Index Medicus, the Directory of Open Access Journals, and the LILACS/BIREME/SCIELO database. Included studies were in English, published after 1992, and reported safety, cost, or outcomes of laparoscopy in LMICs. Studies pertaining to arthroscopy, ENT, flexible endoscopy, hysteroscopy, cystoscopy, computer-assisted surgery, pediatrics, transplantation, and bariatrics were excluded. Qualitative synthesis was performed by extracting results that fell into three categories: advantages of, challenges to, and adaptations made to implement laparoscopy in LMICs. PRISMA guidelines for systematic reviews were followed.A total of 1101 abstracts were reviewed, and 58 articles were included describing laparoscopy in 25 LMICs. Laparoscopy is particularly advantageous in LMICs, where there is often poor sanitation, limited diagnostic imaging, fewer hospital beds, higher rates of hemorrhage, rising rates of trauma, and single income households. Lack of trained personnel and equipment were frequently cited challenges. Adaptive strategies included mechanical insufflation with room air, syringe suction, homemade endoloops, hand-assisted techniques, extracorporeal knot tying, innovative use of cheaper instruments, and reuse of disposable instruments. Inexpensive laboratory-based trainers and telemedicine are effective for training.LMICs face many surgical challenges that require innovation. Laparoscopic surgery may be safe, effective, feasible, and cost-effective in LMICs, although it often remains limited in its accessibility, acceptability, and quality. This study may not capture articles written in languages other than English or in journals not indexed by the included databases. Surgeons, policymakers, and manufacturers should focus on plans for sustainability, training and retention of providers, and regulation of efforts to develop laparoscopy in LMICs.
View details for DOI 10.1007/s00464-015-4201-2
View details for Web of Science ID 000369334600001
View details for PubMedID 25875087
Building a global surgery initiative through evaluation, collaboration, and training: the Massachusetts General Hospital experience.
Journal of surgical education
2015; 72 (4): e21–8
OBJECTIVE: The Massachusetts General Hospital (MGH) Department of Surgery established the Global Surgery Initiative (GSI) in 2013 to transform volunteer and mission-based global surgery efforts into an educational experience in surgical systems strengthening. The objective of this newly conceived mission is not only to perform advanced surgery but also to train surgeons beyond MGH through international partnerships across disciplines. At its inception, a clear pathway to achieve this was not established, and we sought to identify steps that were critical to realizing our mission statement.SETTING: Massachusetts General Hospital, Boston, MA, USA and Mbarara Regional Referral Hospital, Mbarara, UgandaPARTICIPANTS: Members of the MGH and MRRH Departments of Surgery including faculty, fellows, and residentsRESULTS: The MGH GSI steering committee identified 4 steps for sustaining a robust global surgery program: (1) administer a survey to the MGH departmental faculty, fellows, and residents to gauge levels of experience and interest, (2) catalog all ongoing global surgical efforts and projects involving MGH surgical faculty, fellows, and residents to identify areas of overlap and opportunities for collaboration, (3) establish a longitudinal partnership with an academic surgical department in a limited-resource setting (Mbarara University of Science and Technology (MUST) at Mbarara Regional Referral Hospital (MRRH)), and (4) design a formal curriculum in global surgery to provide interested surgical residents with structured opportunities for research, education, and clinical work.CONCLUSIONS: By organizing the collective experiences of colleagues, synchronizing efforts of new and former efforts, and leveraging the funding resources available at the local institution, the MGH GSI hopes to provide academic benefit to our foreign partners as well as our trainees through longitudinal collaboration. Providing additional financial and organizational support might encourage more surgeons to become involved in global surgery efforts. Creating a partnership with a hospital in a limited-resource setting and establishing a formal global surgery curriculum for our residents allows for education and longitudinal collaboration. We believe this is a replicable model for building other academic global surgery endeavors that aim to strengthen health and surgical systems beyond their own institutions.
View details for DOI 10.1016/j.jsurg.2014.12.018
View details for PubMedID 25697510
Estimate of the global volume of surgery in 2012: an assessment supporting improved health outcomes.
2015; 385: S11-?
It was previously estimated that 234·2 million operations were performed worldwide in 2004. The association between surgical rates and population health outcomes is not clear. We re-estimated global surgical volume to track changes over time and assess rates associated with healthy populations.We gathered demographic, health, and economic data for 194 WHO member states. Surgical volumes were obtained from published studies and other reports from 2005 onwards. We estimated rates of surgery for all countries without available data based on health expenditure in 2012 and assessed the proportion of surgery comprised by caesarean delivery. The rate of surgery was plotted against life expectancy to describe the association between surgical care and this health indicator.We identified 66 countries reporting surgical data between 2005 and 2013. We estimate that 312·9 million operations (95% CI 266·2-359·5) took place in 2012-a 33·6% increase over 8 years; the largest proportional increase occurred in countries spending US$400 or less per capita on health care. Caesarean delivery comprised 29·8% (5·8 million operations) of the total surgical volume in poor health expenditure countries compared with 10·8% (7·8 million operations) in low health expenditure countries and 2·7% (5·1 million operations) in high health expenditure countries. We noted a correlation between increased life expectancy and increased surgical rates up to 1533 operations per 100 000 people, with significant but less dramatic improvement above this rate.Surgical volume is large and continues to grow in all economic environments. A single procedure-caesarean delivery-comprised almost a third of surgical volume in the most resource-limited settings. Surgical care is an essential part of health care and is associated with increased life expectancy, yet many low-income countries fail to achieve basic levels of service. Improvements in capacity and delivery of surgical services must be a major component of health system strengthening.None.
View details for DOI 10.1016/S0140-6736(15)60806-6
View details for PubMedID 26313057
- Strategies for last mile implementation of global health technologies. The Lancet. Global health 2014; 2 (9): e497-8
Cost-effectiveness of surgery and its policy implications for global health: a systematic review and analysis
LANCET GLOBAL HEALTH
2014; 2 (6): E334-E345
The perception of surgery as expensive and complex might be a barrier to its widespread acceptance in global health efforts. We did a systematic review and analysis of cost-effectiveness studies that assess surgical interventions in low-income and middle-income countries to help quantify the potential value of surgery.We searched Medline for all relevant articles published between Jan 1, 1996 and Jan 31, 2013, and searched the reference lists of retrieved articles. We converted all results to 2012 US$. We extracted cost-effectiveness ratios (CERs) and appraised economic assessments for their methodological quality using the 10-point Drummond checklist.Of the 584 identified studies, 26 met full inclusion criteria. Together, these studies gave 121 independent CERs in seven categories of surgical interventions. The median CER of circumcision ($13·78 per disability-adjusted life year [DALY]) was similar to that of standard vaccinations ($12·96-25·93 per DALY) and bednets for malaria prevention ($6·48-22·04 per DALY). Median CERs of cleft lip or palate repair ($47·74 per DALY), general surgery ($82·32 per DALY), hydrocephalus surgery ($108·74 per DALY), and ophthalmic surgery ($136 per DALY) were similar to that of the BCG vaccine ($51·86-220·39 per DALY). Median CERs of caesarean sections ($315·12 per DALY) and orthopaedic surgery ($381·15 per DALY) are more favourable than those of medical treatment for ischaemic heart disease ($500·41-706·54 per DALY) and HIV treatment with multidrug antiretroviral therapy ($453·74-648·20 per DALY).Our findings suggest that many essential surgical interventions are cost-effective or very cost-effective in resource-poor countries. Quantification of the economic value of surgery provides a strong argument for the expansion of global surgery's role in the global health movement. However, economic value should not be the only argument for resource allocation--other organisational, ethical, and political arguments can also be made for its inclusion.
View details for Web of Science ID 000336425200017
Prioritizing essential surgery and safe anesthesia for the Post-2015 Development Agenda: Operative capacities of 78 district hospitals in 7 low- and middle-income countries
2014; 155 (3): 365-373
Surgery has been neglected in low- and middle-income countries for decades. It is vital that the Post-2015 Development Agenda reflect that surgery is an important part of a comprehensive global health care delivery model. We compare the operative capacities of multiple low- and middle-income countries and identify critical gaps in surgical infrastructure.The Harvard Humanitarian Initiative survey tool was used to assess the operative capacities of 78 government district hospitals in Bangladesh (n = 7), Bolivia (n = 11), Ethiopia (n = 6), Liberia (n = 11), Nicaragua (n = 10), Rwanda (n = 21), and Uganda (n = 12) from 2011 to 2012. Key outcome measures included infrastructure, equipment availability, physician and nonphysician surgical providers, operative volume, and pharmaceutical capacity.Seventy of 78 district hospitals performed operations. There was fewer than one surgeon or anesthesiologist per 100,000 catchment population in all countries except Bolivia. There were no physician anesthesiologists in any surveyed hospitals in Rwanda, Liberia, Uganda, or in the majority of hospitals in Ethiopia. Mean annual operations per hospital ranged from 374 in Nicaragua to 3,215 in Bangladesh. Emergency operations and obstetric operations constituted 57.5% and 40% of all operations performed, respectively. Availability of pulse oximetry, essential medicines, and key infrastructure (water, electricity, oxygen) varied widely between and within countries.The need for operative procedures is not being met by the limited operative capacity in numerous low- and middle-income countries. It is of paramount importance that this gap be addressed by prioritizing essential surgery and safe anesthesia in the Post-2015 Development Agenda.
View details for DOI 10.1016/j.eurg.2013.10.008
View details for Web of Science ID 000331991200001
View details for PubMedID 24439745
Survey of Surgery and Anesthesia Infrastructure in Ethiopia
WORLD JOURNAL OF SURGERY
2012; 36 (11): 2545–53
Information regarding surgical capacity in the developing world is limited by the paucity of available data regarding surgical care, infrastructure, and human resources in the literature. The purpose of this study was to assess surgical and anesthesia infrastructure and human resources in Ethiopia as part of a larger study by the Harvard Humanitarian Initiative examining surgical and anesthesia capacity in ten low-income countries in Africa.A comprehensive survey tool developed by the Harvard Humanitarian Initiative was used to assess surgical capacity of hospitals in Ethiopia. A total of 20 hospitals were surveyed through convenience sampling. Eight areas of surgical and anesthesia care were examined, including access and availability, access to human resources, infrastructure, outcomes, operating room information and procedures, equipment, nongovernmental organization delivery of surgical services, and pharmaceuticals. Results were obtained over a 1-month period during October 2011.There is wide variation in accessibility, with hospital-to-population ratios ranging from 1:99,010 to 1:1,082,761. The overall physician to population ratio ranges from 1:4715 to 1:107,602. The average hospital has one to two operating rooms, 4.2 surgeons, one gynecologist, and 4.5 anesthesia providers-although in all but three hospitals anesthesiology was provided by nonphysician personnel only (i.e., a nurse anesthetist). Access to continuous electricity, running water, essential medications, and monitoring systems is very limited in all hospitals surveyed, although such access did vary across regions.This survey of Ethiopia's hospital resources attempts to identify specific areas of need where resources, education, and development can be targeted. Because the major surgical mortality comes from late presentations, increasing accessibility through infrastructure development would likely provide a major improvement in surgical morbidity and mortality rates. Infrastructure limitations of electricity, water, oxygen, and blood banking do not prove to be significant barriers to surgical care. The increasing number of physicians is promising, although efforts should be directed specifically toward increasing the number of anesthesiologists and surgeons in the country.
View details for DOI 10.1007/s00268-012-1729-3
View details for Web of Science ID 000309560500001
View details for PubMedID 22851147