Yesim Tozan
Yesim Tozan
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Associate Professor of Global and Environmental Health
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Professional overview
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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.”
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Education
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BS, Environmental Engineering, Istanbul Technical University, TurkeyMS, Environmental Technology, Bogazici University, TurkeyMA, Public Affairs, Princeton University, Princeton, NJPhD, Public Affairs, Princeton University, Princeton, NJ
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Areas of research and study
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Cost EffectivenessCost-effective Health Programs and PoliciesEconomic EvaluationHealth EconomicsInfectious DiseasesPrevention Interventions
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Publications
Publications
Use of insecticide-treated school uniforms for prevention of dengue in schoolchildren: A cost-effectiveness analysis
AbstractTozan, Y., Ratanawong, P., Louis, V. R., Kittayapong, P., & Wilder-Smith, A. (n.d.).Publication year
2014Journal title
PloS oneVolume
9Issue
9AbstractBackground: Dengue-related illness is a leading cause of hospitalization and death, particularly among children. Practical, acceptable and affordable measures are urgently needed to protect this age group. Schools where children spend most of their day is proposed as an ideal setting to implement preventive strategies against day-biting Aedes mosquitoes. The use of insecticide-treated school uniforms is a promising strategy currently under investigation.Methods: Using a decision-analytic model, we evaluated the cost-effectiveness of the use of insecticide-treated school uniforms for prevention of dengue, compared with a ''do-nothing'' alternative, in schoolchildren from the societal perspective. We explored how the potential economic value of the intervention varied under various scenarios of intervention effectiveness and cost, as well as dengue infection risk in school-aged children, using data specific to Thailand.Results: At an average dengue incidence rate of 5.8% per year in school-aged children, the intervention was cost-effective (ICER≤$16,440) in a variety of scenarios when the intervention cost per child was $5.3 or less and the intervention effectiveness was 50% or higher. In fact, the intervention was cost saving (ICER,0) in all scenarios in which the intervention cost per child was $2.9 or less per year and the intervention effectiveness was 50% or higher. The results suggested that this intervention would be of no interest to Thai policy makers when the intervention cost per child was $10.6 or higher per year regardless of intervention effectiveness (ICER>$16,440).Conclusions: Our results present the potential economic value of the use of insecticide-treated uniforms for prevention of dengue in schoolchildren in a typical dengue endemic setting and highlight the urgent need for additional research on this intervention.Dengue Research Funded by the European Commission-Scientific Strategies of Three European Dengue Research Consortia
Jaenisch, T., Sakuntabhai, A., Wilder-smith, A., & Tozan, Y. (n.d.).Publication year
2013Journal title
PLoS Neglected Tropical DiseasesVolume
7Issue
12Page(s)
e2320Evaluation of the Affordable Medicines Facility - Malaria
Tozan, Y., Jahn, A., & Müller, O. (n.d.). In The Lancet (1–).Publication year
2013Volume
381Issue
9872Page(s)
1095Moving towards universal coverage with malaria control interventions: Achievements and challenges in rural Burkina Faso
AbstractDe Allegri, M., Louis, V. R., Tiendrébeogo, J., Souares, A., Yé, M., Tozan, Y., Jahn, A., & Mueller, O. (n.d.).Publication year
2013Journal title
International Journal of Health Planning and ManagementVolume
28Issue
1Page(s)
102-121AbstractThis paper reports on a study, which assessed coverage with malaria control interventions in rural Burkina Faso, namely insecticide-treated mosquito nets (ITN) ownership, intermittent preventive treatment (IPTp) for pregnant women and artemisinin-based combination therapy (ACT) for under-five children. The study also addressed the distributional impact of such interventions, with specific reference to equity. The study used data from a representative household survey conducted on 1106 households in the Nouna Health District in 2010. Findings indicated that 59% of all households owned at least one ITN, 66% of all pregnant women received IPT at least once and 34% of under-five children reporting a malaria case were treated with ACT. Multivariate logistic regression revealed that higher socio-economic status, ownership of at least one radio and living in a village within a Health and Demographic Surveillance System were significantly positively associated with ITN, IPTp and ACT coverage. ITN coverage was higher among households in villages, which had previously hosted an ITN trial and/or the most favourable arm of a trial. Comparing current findings with previous estimates suggests that the country has made substantial progress towards scaling up malaria control interventions but that current coverage rates are still far from achieving the universal coverage targets set by the Roll Back Malaria Partnership. In addition, current coverage patterns reveal the existence of multiple inequities across groups, suggesting that current policies are inadequate to achieve equitable scaling up. Future planning of malaria control interventions ought to take into consideration current inadequacies and lead to programmes better designed to overcome them.Dengue tools: Innovative tools and strategies for the surveillance and control of dengue
AbstractWilder-Smith, A., Renhorn, K. E., Tissera, H., Bakar, S. A., Alphey, L., Kittayapong, P., Lindsay, S., Logan, J., Hatz, C., Reiter, P., Rocklöv, J., Byass, P., Louis, V. R., Tozan, Y., Massad, E., Tenorio, A., Lagneau, C., L’Ambert, G., Brooks, D., … Gubler, D. (n.d.).Publication year
2012Journal title
Global Health ActionVolume
5Issue
1AbstractDengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change.The consortium comprises 12 work packages to address a set of research questions in three areas:Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring.Research area 2: Develop novel strategies to prevent dengue in children.Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change.In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.Pre-referral rectal artesunate treatment of childhood malaria in the community: Training manual and for community health workers to assess danger signs, provide emergency pre-referral treatment and refer treated children to a health facility
Tozan, Y., & Gomez, M. (n.d.). (1–).Publication year
2012The impact of insecticide-treated school uniforms on dengue infections in school-aged children: Study protocol for a randomised controlled trial in Thailand
AbstractWilder-Smith, A., Byass, P., Olanratmanee, P., Maskhao, P., Sringernyuang, L., Logan, J. G., Lindsay, S. W., Banks, S., Gubler, D., Louis, V. R., Tozan, Y., & Kittayapong, P. (n.d.).Publication year
2012Journal title
TrialsVolume
13AbstractBackground: There is an urgent need to protect children against dengue since this age group is particularly sensitive to the disease. Since dengue vectors are active mainly during the day, a potential target for control should be schools where children spend a considerable amount of their day. School uniforms are the cultural norm in most developing countries, worn throughout the day. We hypothesise that insecticide-treated school uniforms will reduce the incidence of dengue infection in school-aged children. Our objective is to determine the impact of impregnated school uniforms on dengue incidence.Methods: A randomised controlled trial will be conducted in eastern Thailand in a group of schools with approximately 2,000 students aged 7-18 years. Pre-fabricated school uniforms will be commercially treated to ensure consistent, high-quality insecticide impregnation with permethrin. A double-blind, randomised, crossover trial at the school level will cover two dengue transmission seasons.Discussion: Practical issues and plans concerning intervention implementation, evaluation, analysing and interpreting the data, and possible policy implications arising from the trial are discussed.Trial registration: clinicaltrial.gov. Registration number: NCT01563640.Social determinants approaches to public health
Failed generating bibliography.Publication year
2011Prereferral rectal artesunate for treatment of severe childhood malaria: A cost-effectiveness analysis
AbstractTozan, Y., Klein, E. Y., Darley, S., Panicker, R., Laxminarayan, R., & Breman, J. G. (n.d.).Publication year
2010Journal title
The LancetVolume
376Issue
9756Page(s)
1910-1915AbstractSeverely ill patients with malaria with vomiting, prostration, and altered consciousness cannot be treated orally and need injections. In rural areas, access to health facilities that provide parenteral antimalarial treatment is poor. Safe and effective treatment of most severe malaria cases is delayed or not achieved. Rectal artesunate interrupts disease progression by rapidly reducing parasite density, but should be followed by further antimalarial treatment. We estimated the cost-effectiveness of community-based prereferral artesunate treatment of children suspected to have severe malaria in areas with poor access to formal health care. We assessed the cost-effectiveness (in international dollars) of the intervention from the provider perspective. We studied a cohort of 1000 newborn babies until 5 years of age. The analysis assessed how the cost-effectiveness results changed with low (25), moderate (50), high (75), and full (100) referral compliance and intervention uptake. At low intervention uptake and referral compliance (25), the intervention was estimated to avert 19 disability-adjusted life-years (DALYs; 95 CI 16-21) and to cost I$1173 (95 CI 1050-1297) per DALY averted. Under the full uptake and compliance scenario (100), the intervention could avert 967 DALYs (884-1050) at a cost of I$77 (73-81) per DALY averted. Prereferral artesunate treatment is a cost-effective, life-saving intervention, which can substantially improve the management of severe childhood malaria in rural African settings in which programmes for community health workers are in place. The Disease Control Priorities Project; Fogarty International Center; US National Institutes of Health; and the Peter Paul Career Development Professorship, Boston University.Prereferral rectal artesunate for treatment of severe childhood malaria: a cost-effectiveness analysis
Klein, E. Y., Darley, S., Panicker, R., Laxminarayan, R., Breman, J. G., & Tozan, Y. (n.d.).Publication year
2010Journal title
The LancetVolume
376Issue
9756Page(s)
1910-1915Dichlorodiphenyltrichloroethane (DDT) for indoor residual spraying in Africa: How can it be used for malaria control?
AbstractSadasivaiah, S., Tozan, Y., & Breman, J. G. (n.d.).Publication year
2007Journal title
American Journal of Tropical Medicine and HygieneVolume
77Page(s)
249-263AbstractIn 2006, the World Health Organization issued a position statement promoting the use of indoor residual spraying (IRS) with dichlorodiphenyltrichloroethane (DDT) for malaria vector control in epidemic and endemic areas. Other international organizations concurred because of the great burden of malaria and the relative ineffectiveness of current treatment and control strategies. Although the Stockholm Convention of 2001 targeted DDT as 1 of 12 persistent organic pollutants for phase-out and eventual elimination, it allowed a provision for its continued indoor use for disease vector control. Although DDT is a low-cost antimalarial tool, the possible adverse human health and environmental effects of exposure through IRS must be carefully weighed against the benefits to malaria control. This article discusses the controversy surrounding the use of DDT for IRS; its effective implementation in Africa; recommendations for deployment today, and training, monitoring, and research needs for effective and sustainable implementation. We consider the costs and cost effectiveness of IRS with DDT, alternative insecticides to DDT, and the importance of integrated vector control if toxicity, resistance, and other issues restrict its use.Coming to grips with malaria in the new millennium
Teklehaimanot, A., & Tozan, Y. (n.d.). (1–).Publication year
2005Emerging consensus in HIV/AIDS, malaria, tuberculosis, and access to essential medicines
Ruxin, J., Paluzzi, J. E., Wilson, P. A., Tozan, Y., Kruk, M., & Teklehaimanot, A. (n.d.).Publication year
2005Journal title
LancetVolume
365Issue
9459Page(s)
618-621The economic payoffs of integrated malaria control in the Zambian copperbelt between 1930 and 1950
AbstractUtzinger, J., Tozan, Y., Doumani, F., & Singer, B. H. (n.d.).Publication year
2002Journal title
Tropical Medicine and International HealthVolume
7Issue
8Page(s)
657-677AbstractIt has long been suggested that malaria is delaying the economic development of countries that are most severely affected by the disease. Several studies have documented the economic consequences of malaria at the household level, primarily in communities engaged in subsistence farming. A missing element is the appraisal of the economic impact of malaria on the industrial and service sectors that will probably become the backbone of many developing economies. We estimate the economic effects of integrated malaria control implemented during the colonial period and sustained for 20 years in four copper mining communities of the former Northern Rhodesia (now Zambia). Integrated malaria control was characterized by strong emphasis on environmental management, while part of the mining communities also benefited from rapid diagnosis and treatment and the use of bednets. The programmes were highly successful as an estimated 14 122 deaths, 517 284 malaria attacks and 942 347 work shift losses were averted. Overall, 127 226 disability adjusted life years (DALYs) were averted per 3-year incremental period. The cumulative costs of malaria control interventions were US$ 11 169 472 (in 1995 US$). Because the control programmes were so effective, the mining companies attracted a large reservoir of migrant labourers and sustained healthy work forces. The programmes averted an estimated US$ 796 622 in direct treatment costs and US$ 5 678 745 in indirect costs as a result of reduced work absenteeism. Within a few years of programme initiation, Northern Rhodesia became the leading copper producer in Africa, and mining generated the dominant share of national income. Copper production and revenues, which increased dramatically during malaria control interventions, amounted to the equivalent of US$ 7.1 billion (in 1995 US$). Integrated malaria control in copper mining communities was a sound investment. It had payoff for public and occupational health, generally, and without it copper extraction and social and economic development would have been impossible.Efficacy and cost-effectiveness of environmental management for malaria control
AbstractUtzinger, J., Tozan, Y., & Singer, B. H. (n.d.).Publication year
2001Journal title
Tropical Medicine and International HealthVolume
6Issue
9Page(s)
677-687AbstractRoll back malaria (RBM) aims at halving the current burden of the disease by the year 2010. The focus is on sub-Saharan Africa, and it is proposed to implement efficacious and cost-effective control strategies. But the evidence base of such information is scarce, and a notable missing element is the discussion of the potential of environmental management. We reviewed the literature and identified multiple malaria control programmes that incorporated environmental management as the central feature. Prominent among them are programmes launched in 1929 and implemented for two decades at copper mining communities in Zambia. The full package of control measures consisted of vegetation clearance, modification of river boundaries, draining swamps, oil application to open water bodies and house screening. Part of the population also was given quinine and was sleeping under mosquito nets. Monthly malaria incidence rates and vector densities were used for surveillance and adaptive tuning of the environmental management strategies to achieve a high level of performance. Within 3-5 years, malaria-related mortality, morbidity and incidence rates were reduced by 70-95%. Over the entire 20 years of implementation, the programme had averted an estimated 4173 deaths and 161 205 malaria attacks. The estimated costs per death and malaria attack averted were US$ 858 and US$ 22.20, respectively. Over the initial 3-5 years start-up period, analogous to the short-duration of cost-effectiveness analyses of current studies, we estimated that the costs per disability adjusted life year (DALY) averted were US$ 524-591. However, the strategy has a track record of becoming cost-effective in the longer term, as maintenance costs were much lower: US$ 22-92 per DALY averted. In view of fewer adverse ecological effects, increased sustainability and better uses of local resources and knowledge, environmental management - integrated with pharmacological, insecticidal and bednet interventions - could substantially increase the chances of rolling back malaria.