Assistant Professor of Global Health
Dr. Yesim Tozan’s research centers on health decision science and priority setting, and explores the costs and cost-effectiveness of health care interventions using decision analytic models and the issues of health care resource allocation in low- and middle-income countries. Her main focus has been infectious disease prevention and control with an emphasis on dengue and malaria. Dr. Tozan is currently leading a health economics work package in a European Union-funded research project on dengue surveillance and control with field sites in Sri Lanka and Thailand. She is also leading a prospective multi-center study on the cost of dengue illness in international travelers utilizing a network of travel clinics in Europe, the US, the Middle East and Australia. Most recently, she has been working on economic evaluation of artemisinin-based combination therapies for the treatment of uncomplicated childhood malaria using data from multi-site randomized clinical trials in Africa and Asia. Dr. Tozan was a task force associate for the UN Millennium Project’s Task Force on HIV/AIDS, Malaria, Tuberculosis and Access to Essential Medicines and was lead author of the malaria task force report entitled “Coming to grips with malaria in the new millennium.”
BS, Environmental Engineering, Istanbul Technical University, TurkeyMS, Environmental Technology, Bogazici University, TurkeyMA, Public Affairs, Princeton University, Princeton, NJPhD, Public Affairs, Princeton University, Princeton, NJ
Cost EffectivenessCost-effective Health Programs and PoliciesEconomic EvaluationHealth EconomicsInfectious DiseasesPrevention Interventions
Reviewing estimates of the basic reproduction number for dengue, Zika and chikungunya across global climate zones
Severe dengue epidemic, Sri Lanka, 2017
Social media as a recruitment platform for a nationwide online survey of COVID-19 knowledge, beliefs, and practices in the United States: Methodology and feasibility analysisAli, S. H., Foreman, J., Capasso, A., Jones, A. M., Tozan, Y., & Diclemente, R. J.
Journal titleBMC Medical Research Methodology
Issue1AbstractBackground: The COVID-19 pandemic has evolved into one of the most impactful health crises in modern history, compelling researchers to explore innovative ways to efficiently collect public health data in a timely manner. Social media platforms have been explored as a research recruitment tool in other settings; however, their feasibility for collecting representative survey data during infectious disease epidemics remain unexplored. Objectives: This study has two aims 1) describe the methodology used to recruit a nationwide sample of adults residing in the United States (U.S.) to participate in a survey on COVID-19 knowledge, beliefs, and practices, and 2) outline the preliminary findings related to recruitment, challenges using social media as a recruitment platform, and strategies used to address these challenges. Methods: An original web-based survey informed by evidence from past literature and validated scales was developed. A Facebook advertisement campaign was used to disseminate the link to an online Qualtrics survey between March 20-30, 2020. Two supplementary male-only and racial minority- targeted advertisements were created on the sixth and tenth day of recruitment, respectively, to address issues of disproportionate female- and White-oriented gender- and ethnic-skewing observed in the advertisement's reach and response trends. Results: In total, 6602 participant responses were recorded with representation from all U.S. 50 states, the District of Columbia, and Puerto Rico. The advertisements cumulatively reached 236,017 individuals and resulted in 9609 clicks (4.07% reach). Total cost of the advertisement was $906, resulting in costs of .09 per click and .18 per full response (completed surveys). Implementation of the male-only advertisement improved the cumulative percentage of male respondents from approximately 20 to 40%. Conclusions: The social media advertisement campaign was an effective and efficient strategy to collect large scale, nationwide data on COVID-19 within a short time period. Although the proportion of men who completed the survey was lower than those who didn't, interventions to increase male responses and enhance representativeness were successful. These findings can inform future research on the use of social media recruitment for the rapid collection of survey data related to rapidly evolving health crises, such as COVID-19.
The Mosquito, the Virus, the Climate: An Unforeseen Réunion in 2018
Transmission dynamics of dengue and chikungunya in a changing climate: do we understand the eco-evolutionary response?
Trends and predictors of COVID-19 information sources and their relationship with knowledge and beliefs related to the pandemic: Nationwide cross-sectional studyAli, S. H., Foreman, J., Tozan, Y., Capasso, A., Jones, A. M., & DiClemente, R. J.
Journal titleJMIR Public Health and Surveillance
Issue4AbstractBackground: During the COVID-19 pandemic, there is a heightened need to understand health information seeking behaviors to address disparities in knowledge and beliefs about the crisis. Objective: This study assessed sociodemographic predictors of the use and trust of different COVID-19 information sources, as well as the association between information sources and knowledge and beliefs about the pandemic. Methods: An online survey was conducted among US adults in two rounds during March and April 2020 using advertisement-based recruitment on social media. Participants were asked about their use of 11 different COVID-19 information sources as well as their most trusted source of information. The selection of COVID-related knowledge and belief questions was based on past empirical literature and salient concerns at the time of survey implementation. Results: The sample consisted of 11,242 participants. When combined, traditional media sources (television, radio, podcasts, or newspapers) were the largest sources of COVID-19 information (91.2%). Among those using mainstream media sources for COVID-19 information (n=7811, 69.5%), popular outlets included CNN (24.0%), Fox News (19.3%), and other local or national networks (35.2%). The largest individual information source was government websites (87.6%). They were also the most trusted source of information (43.3%), although the odds of trusting government websites were lower among males (adjusted odds ratio [AOR] 0.58, 95% CI 0.53-0.63) and those aged 40-59 years and ≥60 years compared to those aged 18-39 years (AOR 0.83, 95% CI 0.74-0.92; AOR 0.62, 95% CI 0.54-0.71). Participants used an average of 6.1 sources (SD 2.3). Participants who were male, aged 40-59 years or ≥60 years; not working, unemployed, or retired; or Republican were likely to use fewer sources while those with children and higher educational attainment were likely to use more sources. Participants surveyed in April were markedly less likely to use (AOR 0.41, 95% CI 0.35-0.46) and trust (AOR 0.51, 95% CI 0.47-0.56) government sources. The association between information source and COVID-19 knowledge was mixed, while many COVID-19 beliefs were significantly predicted by information source; similar trends were observed with reliance on different types of mainstream media outlets. Conclusions: COVID-19 information source was significantly determined by participant sociodemographic characteristics and was also associated with both knowledge and beliefs about the pandemic. Study findings can help inform COVID-19 health communication campaigns and highlight the impact of using a variety of different and trusted information sources.
A combination intervention addressing sexual risk-taking behaviors among vulnerable women in Uganda: Study protocol for a cluster randomized clinical trial
A combination of incidence data and mobility proxies from social media predicts the intraurban spread of dengue in Yogyakarta, Indonesia
A prospective study on the impact and out-of-pocket costs of dengue illness in international travelers
Evaluation of a savings-led family-based economic empowerment intervention for AIDS-affected adolescents in Uganda: A fouryear follow-up on efficacy and costeffectiveness
Evaluation of intensified dengue control measures with interrupted time series analysis in the Panadura Medical Officer of Health division in Sri Lanka: a case study and cost-effectiveness analysis
Incidence of Guillain-BarréSyndrome (GBS) in Latin America and the Caribbean before and during the 2015-2016 Zika virus epidemic: A systematic review and meta-analysisCapasso, A., Ompad, D. C., Vieira, D. L., Wilder-Smith, A., & Tozan, Y.
Journal titlePLoS neglected tropical diseases
Issue8AbstractBackground A severe neurological disorder, Guillain-Barrésyndrome (GBS) is the leading cause of acute flaccid paralysis. Enhanced surveillance of GBS in Latin America and the Caribbean (LAC) following the 2015-2016 Zika virus (ZIKV) epidemic presents an opportunity to estimate, for the first time, the regional incidence of GBS. Methods and findings For this systematic review and meta-analysis, we searched nine scientific databases and grey literature from January 1, 1980 to October 1, 2018. Sources with primary data on incident GBS cases in LAC within a well-defined population and timeframe, published in English, Spanish, Portuguese, or French, were included. We calculated the annual GBS incidence rates (IRs) and 95% confidence intervals (CIs) for each source based on published data. Following an assessment of heterogeneity, we used random-effects meta-analysis to calculate the pooled annual IR of GBS. The study is registered with PROSPERO, number CRD42018086659. Of the 6568 initial citation hits, 31 were eligible for inclusion. Background annual GBS IRs in Latin America ranged from 0.40 in Brazil to 2.12/100,000 in Chile. The pooled annual IR in the Caribbean was 1.64 (95% CI 1.29-2.12, I2<0.01, p = 0.44). During the ZIKV epidemic, GBS IRs ranged from 0.62 in Mexico to 9.35/100,000 in Martinique. GBS increased 2.6 (95% CI 2.3-2.9) times during ZIKV and 1.9 (95% CI 1.1- 3.4) times during chikungunya outbreaks over background rates. A limitation of this review is that the studies included employed different methodologies to find and ascertain cases of GBS, which could contribute to IR heterogeneity. In addition, it is important to consider that data on GBS are lacking for many countries in the region. Conclusions Background IRs of GBS appear to peak during arboviral disease outbreaks. The current review contributes to an understanding of the epidemiology of GBS in the LAC region, which can inform healthcare system planning and preparedness, particularly during arboviral epidemics.
Using big data to monitor the introduction and spread of Chikungunya, Europe, 2017
Economic burden of caregiving for persons with severe mental illness in sub-Saharan Africa: A systematic review
Novel tools for the surveillance and control of dengue: findings by the dengueTools research consortium
Economic cost and quality of life of family caregivers of schizophrenic patients attending psychiatric hospitals in Ghana
Household costs of hospitalized dengue illness in semi-rural Thailand
Mitigating Diseases Transmitted by Aedes Mosquitoes: A Cluster-Randomised Trial of Permethrin-Impregnated School Uniforms
Using remote sensing environmental data to forecast malaria incidence at a rural district hospital in Western Kenya
A spatial hierarchical analysis of the temporal influences of the el niño-southern oscillation and weather on dengue in Kalutara District, Sri Lanka
Characteristics of and factors associated with dengue vector breeding sites in the City of Colombo, Sri Lanka
Costs of Dengue Control Activities and Hospitalizations in the Public Health Sector during an Epidemic Year in Urban Sri Lanka
Current issues in the economics of vaccination against dengue
Internet-based media coverage on dengue in Sri Lanka between 2007 and 2015
Spatial variations in dengue transmission in schools in Thailand