Yesim Tozan
Yesim Tozan
Scroll
Associate Professor of Global and Environmental Health
-
Professional overview
-
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.”
-
Education
-
BS, Environmental Engineering, Istanbul Technical University, TurkeyMS, Environmental Technology, Bogazici University, TurkeyMA, Public Affairs, Princeton University, Princeton, NJPhD, Public Affairs, Princeton University, Princeton, NJ
-
Areas of research and study
-
Cost EffectivenessCost-effective Health Programs and PoliciesEconomic EvaluationHealth EconomicsInfectious DiseasesPrevention Interventions
-
Publications
Publications
Knowledge, beliefs, mental health, substance use, and behaviors related to the COVID-19 pandemic among US adults: a national online survey
AbstractDiClemente, R. J., Capasso, A., Ali, S. H., Jones, A. M., Foreman, J., & Tozan, Y. (n.d.).Publication year
2022Journal title
Zeitschrift fur GesundheitswissenschaftenVolume
30Issue
8Page(s)
2069-2079AbstractAIM: Given the need for data to inform public health messaging to mitigate the COVID-19 pandemic, this national survey sought to assess the state of COVID-19-related knowledge, beliefs, mental health, substance use changes, and behaviors among a sample of U.S. adults.SUBJECT AND METHODS: In the period March 20-30, 2020, we collected data on COVID-19-related knowledge, awareness and adoption of preventive practices, depression and anxiety (Patient Health Questionnaire-4), stress (Impact of Event Scale-6), pessimism, and tobacco and alcohol use. Differences between age groups (18-39 years, 40-59 years and ≥ 60 years) were tested using Pearson's chi-squared tests or ANOVAs; associations between drinking and smoking and depression, anxiety, and stress were tested using adjusted logistic regression models.RESULTS: Approximately half of the sample ( N Total = 6391) were 50-69 years old and 58% were female. COVID-19 knowledge (mean = 12.0; SD = 1.2) and protective practice awareness (mean = 9.1; SD = 0.8) were high. Among respondents, 44% had a score consistent with depression and anxiety (PHQ-4 score ≥ 6), and 52% reported high stress scores (≥ median of 1.33). COVID-19-related anxiety and depression were associated with increased drinking (AOR = 1.79; 95% CI = 1.49, 2.15) and smoking (AOR = 2.17; 95% CI = 1.64, 2.88). High stress scores were also associated with increased drinking (AOR = 1.80; 95% CI = 1.49, 2.17, p < 0.001) and smoking (AOR = 1.75; 95% CI = 1.31, 2.33). CONCLUSIONS: In spite of high knowledge levels, important gaps were identified. High prevalence of poor mental health outcomes and associated increases in drinking and smoking warrant ongoing risk communications tailoring to effectively disseminate information and expanding psychosocial services, particularly via telehealth, to mitigate the negative mental health impact of COVID-19.SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10389-021-01564-4.PrEP acceptability and initiation among women engaged in sex work in Uganda: Implications for HIV prevention
AbstractWitte, S. S., Filippone, P., Ssewamala, F. M., Nabunya, P., Bahar, O. S., Mayo-Wilson, L. J., Namuwonge, F., Damulira, C., Tozan, Y., Kiyingi, J., Nabayinda, J., Mwebembezi, A., Kagaayi, J., & McKay, M. (n.d.).Publication year
2022Journal title
EClinicalMedicineVolume
44AbstractBackground: Women engaged in sex work (WESW) are disproportionately affected by HIV. In Uganda, HIV prevalence among WESW is estimated at 37%, accounting for 18% of all new infections in the country. WESW experience poverty, gender-based violence, and other issues that reduce their power and limit their ability to negotiate condom use. Female-controlled strategies, including pre-exposure prophylaxis (PrEP), may afford women more transmission protection, but barriers to access and use persist. This cross-sectional study examined baseline PrEP acceptability and initiation among WESW recently enrolled in a randomized clinical trial in Uganda to test the impact of a combination HIV risk reduction and economic empowerment intervention on sexual risk outcomes (clinicaltrials.gov, NCT03583541). Methods: A total of 542 WESW from 19 high HIV-prevalent geographical areas were enrolled in the Kyaterekera study between June 2019 and March 2020. Women were eligible for the study if they: (1) were age 18 or over; (2) reported engagement in transactional sex (a sex act in exchange for pay) in the past 30 days; and (3) reported engagement in one or more episodes of unprotected sex in the past 30 days. Women completed a baseline assessment, were tested for HIV and other sexually transmitted infections (STIs) at enrollment, and were connected with antiretroviral therapy (ART), STI treatment, or PrEP, based on need and interest. Descriptive statistics examined baseline data on PrEP acceptability and initiation. Independent variables (i.e. years in sex work, recent sexual coercion, perceived HIV and sex work stigmas, harmful alcohol use, barriers to medical care, and social support) were derived from the empirical literature and women's self-report. Bivariate analysis was performed to test associations between main effects of these variables. Using binomial logistic regression, predictive models were evaluated for two distinct outcomes—PrEP acceptability and PrEP initiation/uptake. Findings: At baseline, 59% of women (n = 322) tested HIV negative. Among WESW testing negative, 11% (n = 36) were already PrEP enrolled. Most women reported willingness to use PrEP (n = 317; 91%). Slightly over half of WESW not already on PrEP agreed to initiate PrEP (n = 158; 55%). Logistic regression models demonstrate that acceptability of or willingness to use PrEP was significantly associated with fewer years engaged in sex work (AOR= ·18, 95% CI 0·05-·66, p<·01) and greater perceived social support from family (AOR= 1·39, 95% CI 1·03 -1.88, p<·05). PrEP initiation was negatively associated with greater perceived social support from friends (AOR=·81, 95% CI ·68–0·97, p<·05) and positively associated with higher perceived stigma due to sex work among family members (AOR=2·20, 95% CI 1·15–4·22, p<·05). Interpretation: Despite endorsing PrEP use, many WESW remain reluctant to use it. This gap in prevention practice highlights the heart of a failing PrEP prevention cascade. Findings point to the important role family and friend support may play in destigmatizing sex work and PrEP use for women. Social and structural-level efforts are needed to improve educational messaging and to integrate positive messaging into health promotion campaigns for women and their families, while also working toward decriminalizing sex work. Funding: This paper was made possible with funding from United States National Institute of Mental Health (Grant number: R01MH116768).Prevalence and predictors of HIV and sexually transmitted infections among vulnerable women engaged in sex work: Findings from the Kyaterekera Project in Southern Uganda
AbstractKiyingi, J., Nabunya, P., Bahar, O. S., Mayo-Wilson, L. J., Tozan, Y., Nabayinda, J., Namuwonge, F., Nsubuga, E., Kizito, S., Nattabi, J., Nakabuye, F., Kagayi, J., Mwebembezi, A., Witte, S. S., & Ssewamala, F. M. (n.d.).Publication year
2022Journal title
PloS oneVolume
17Issue
9AbstractIntroduction Women engaged in sex work (WESW) have an elevated risk of the human immunodeficiency virus (HIV) and sexually transmitted infections (STI). Estimates are three times higher than the general population. Understanding the predictors of HIV and STI among WESW is crucial in developing more focused HIV and STI prevention interventions among this population. The study examined the prevalence and predictors of HIV and STI among WESW in the Southern part of Uganda. Methodology Baseline data from the Kyaterekera study involving 542 WESW (ages 18–55) recruited from 19 HIV hotspots in the greater Masaka region in Uganda was utilized. HIV and STI prevalence was estimated using blood and vaginal fluid samples bioassay. Hierarchical regression models were used to determine the predictors of HIV and STI among WESW. Results Of the total sample, 41% (n = 220) were found to be HIV positive; and 10.5% (n = 57) tested positive for at least one of the three STI (Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis) regardless of their HIV status. Older age (b = 0.09, 95%CI = 0.06, 0.13, p≤0.001), lower levels of education (b = -0.79, 95%CI = -1.46, -0.11, p≤0.05), fewer numbers of children in the household (b = -0.18, 95%CI = -0.36, -0.01), p≤0.05), location (i.e., fishing village (b = 0.51, 95%CI = 0.16, 0.85, p≤0.01) or small town (b = -0.60, 95% CI = -0.92, -0.28, p≤0.001)), drug use (b = 0.58, 95%CI = 0.076, 1.08, p≤0.05) and financial self-efficacy (b = 0.05, 95%CI = -0.10, 0.00, p≤0.05), were associated with the risk of HIV infections among WESW. Domestic violence attitudes (b = -0.24, 95%CI = -0.42, -0.07, p≤0.01) and financial distress (b = -0.07, 95%CI = -0.14, -0.004, p≤0.05) were associated with the risk of STI infection among WESW. Conclusion Study findings show a high prevalence of HIV among WESW compared to the general women population. Individual and family level, behavioural and economic factors were associated with increased HIV and STI infection among WESW. Therefore, there is a need for WESW focused HIV and STI risk reduction and economic empowerment interventions to reduce these burdens.Socioeconomic predictors of COVID-19- related health disparities among United States workers: A structural equation modeling study
AbstractCapasso, A., Kim, S., Ali, S. H., Jones, A. M., DiClemente, R. J., & Tozan, Y. (n.d.).Publication year
2022Journal title
PLOS Global Public HealthVolume
2Issue
2AbstractThe COVID-19 pandemic has disproportionately impacted the physical and mental health, and the economic stability, of specific population subgroups in different ways, deepening existing disparities. Essential workers have faced the greatest risk of exposure to COVID- 19; women have been burdened by caretaking responsibilities; and rural residents have experienced healthcare access barriers. Each of these factors did not occur on their own. While most research has so far focused on individual factors related to COVID-19 disparities, few have explored the complex relationships between the multiple components of COVID-19 vulnerabilities. Using structural equation modeling on a sample of United States (U.S.) workers (N = 2800), we aimed to 1) identify factor clusters that make up specific COVID-19 vulnerabilities, and 2) explore how these vulnerabilities affected specific subgroups, specifically essential workers, women and rural residents. We identified 3 COVID- 19 vulnerabilities: financial, mental health, and healthcare access; 9 out of 10 respondents experienced one; 15% reported all three. Essential workers [standardized coefficient (β) = 0.23; unstandardized coefficient (B) = 0.21, 95% CI = 0.17, 0.24] and rural residents (β = 0.13; B = 0.12, 95% CI = 0.09, 0.16) experienced more financial vulnerability than nonessential workers and non-rural residents, respectively. Women (β = 0.22; B = 0.65, 95% CI = 0.65, 0.74) experienced worse mental health than men; whereas essential workers reported better mental health (β = -0.08; B = -0.25, 95% CI = -0.38, -0.13) than other workers. Rural residents (β = 0.09; B = 0.15, 95% CI = 0.07, 0.24) experienced more healthcare access barriers than non-rural residents. Findings highlight how interrelated financial, mental health, and healthcare access vulnerabilities contribute to the disproportionate COVID- 19-related burden among U.S. workers. Policies to secure employment conditions, including fixed income and paid sick leave, are urgently needed to mitigate pandemic-associated disparities.Universal healthcare coverage and health service delivery before and during the COVID- 19 pandemic: A difference-in-difference study of childhood immunization coverage from 195 countries
AbstractKim, S., Headley, T. Y., & Tozan, Y. (n.d.).Publication year
2022Journal title
PLoS MedicineVolume
19Issue
8AbstractBackground Several studies have indicated that universal health coverage (UHC) improves health service utilization and outcomes in countries. These studies, however, have primarily assessed UHC's peacetime impact, limiting our understanding of UHC's potential protective effects during public health crises such as the Coronavirus Disease 2019 (COVID-19) pandemic. We empirically explored whether countries' progress toward UHC is associated with differential COVID-19 impacts on childhood immunization coverage. Methods and findings Using a quasi-experimental difference-in-difference (DiD) methodology, we quantified the relationship between UHC and childhood immunization coverage before and during the COVID-19 pandemic. The analysis considered 195 World Health Organization (WHO) member states and their ability to provision 12 out of 14 childhood vaccines between 2010 and 2020 as an outcome. We used the 2019 UHC Service Coverage Index (UHC SCI) to divide countries into a "high UHC index"group (UHC SCI ≥80) and the rest. All analyses included potential confounders including the calendar year, countries' income group per the World Bank classification, countries' geographical region as defined by WHO, and countries' preparedness for an epidemic/pandemic as represented by the Global Health Security Index 2019. For robustness, we replicated the analysis using a lower cutoff value of 50 for the UHC index. A total of 20,230 country-year observations were included in the study. The DiD estimators indicated that countries with a high UHC index (UHC SCI ≥80, n = 35) had a 2.70% smaller reduction in childhood immunization coverage during the pandemic year of 2020 as compared to the countries with UHC index less than 80 (DiD coefficient 2.70; 95% CI: 0.75, 4.65; p-value = 0.007). This relationship, however, became statistically nonsignificant at the lower cutoff value of UHC SCI <50 (n = 60). The study's primary limitation was scarce data availability, which restricted our ability to account for confounders and to test our hypothesis for other relevant outcomes. Conclusions We observed that countries with greater progress toward UHC were associated with significantly smaller declines in childhood immunization coverage during the pandemic. This identified association may potentially provide support for the importance of UHC in building health system resilience. Our findings strongly suggest that policymakers should continue to advocate for achieving UHC in coming years.What predicts people’s belief in COVID-19 misinformation? A retrospective study using a nationwide online survey among adults residing in the United States
AbstractKim, S., Capasso, A., Ali, S. H., Headley, T., DiClemente, R. J., & Tozan, Y. (n.d.).Publication year
2022Journal title
BMC public healthVolume
22Issue
1AbstractBackground: Tackling infodemics with flooding misinformation is key to managing the COVID-19 pandemic. Yet only a few studies have attempted to understand the characteristics of the people who believe in misinformation. Methods: Data was used from an online survey that was administered in April 2020 to 6518 English-speaking adult participants in the United States. We created binary variables to represent four misinformation categories related to COVID-19: general COVID-19-related, vaccine/anti-vaccine, COVID-19 as an act of bioterrorism, and mode of transmission. Using binary logistic regression and the LASSO regularization, we then identified the important predictors of belief in each type of misinformation. Nested vector bootstrapping approach was used to estimate the standard error of the LASSO coefficients. Results: About 30% of our sample reported believing in at least one type of COVID-19-related misinformation. Belief in one type of misinformation was not strongly associated with belief in other types. We also identified 58 demographic and socioeconomic factors that predicted people’s susceptibility to at least one type of COVID-19 misinformation. Different groups, characterized by distinct sets of predictors, were susceptible to different types of misinformation. There were 25 predictors for general COVID-19 misinformation, 42 for COVID-19 vaccine, 36 for COVID-19 as an act of bioterrorism, and 27 for mode of COVID-transmission. Conclusion: Our findings confirm the existence of groups with unique characteristics that believe in different types of COVID-19 misinformation. Findings are readily applicable by policymakers to inform careful targeting of misinformation mitigation strategies.Working with economically vulnerable women engaged in sex work: Collaborating with community stakeholders in Southern Uganda
AbstractNabunya, P., Kiyingi, J., Witte, S. S., Sensoy Bahar, O., Jennings Mayo-Wilson, L., Tozan, Y., Nabayinda, J., Mwebembezi, A., Tumwesige, W., Mukasa, B., Namirembe, R., Kagaayi, J., Nakigudde, J., McKay, M. M., & Ssewamala, F. M. (n.d.).Publication year
2022Journal title
Global Public HealthVolume
17Issue
7Page(s)
1215-1231AbstractEconomically vulnerable women engaged in sex work (WESW) comprise one of the key populations with higher prevalence of HIV globally. In Uganda, HIV prevalence among WESW is estimated at 37% and accounts for 18% of all new infections in the country. This paper describes the strategies by which we have engaged community stakeholders in a randomised clinical trial aimed at evaluating the efficacy of adding economic empowerment components to traditional HIV risk reduction to reduce the incidence of STIs and HIV among WESW in Uganda. We demonstrate that stakeholder engagement, including the engagement of WESW themselves, plays a critical role in the adaptation, implementation, uptake, and potential sustainability of evidence-based interventions. To our knowledge, this is the first study to utilise stakeholder engagement involving WESW in Uganda. Researchers working with hard-to-reach populations, such as WESW, are encouraged to invest time and resources to engage key stakeholders through a full range of collaborative activities; and ensure that research is culturally appropriate and meets the needs of all stakeholders involved. Clinical trial registration: ClinicalTrials.gov identifier: NCT03583541.A systematic review of the evidence on the effectiveness and cost-effectiveness of mass screen-and-treat interventions for Malaria control
AbstractKim, S., Luande, V. N., Rocklov, J., Carlton, J. M., & Tozan, Y. (n.d.).Publication year
2021Journal title
American Journal of Tropical Medicine and HygieneVolume
105Issue
6Page(s)
1722-1731AbstractMalaria elimination and eradication efforts have stalled globally. Further, asymptomatic infections as silent transmission reservoirs are considered a major challenge to malaria elimination efforts. There is increased interest in a mass screen-and-treat (MSAT) strategy as an alternative to mass drug administration to reduce malaria burden and transmission in endemic settings. This study systematically synthesized the existing evidence on MSAT, from both epidemiological and economic perspectives. Searches were conducted on six databases (PubMed, EMBASE, CINALH, Web of Science, Global Health, and Google Scholar) between October and December 2020. Only experimental and quasi-experimental studies assessing the effectiveness and/or cost-effectiveness of MSAT in reducing malaria prevalence or incidence were included. Of the 2,424 citation hits, 14 studies based on 11 intervention trials were eligible. Eight trials were conducted in sub-Saharan Africa and three trials in Asia. While five trials targeted the community as a whole, pregnant women were targeted in five trials, and school children in one trial. Transmission setting, frequency, and timing of MSAT rounds, and measured outcomes varied across studies. The pooled effect size of MSAT in reducing malaria incidence and prevalence was marginal and statistically nonsignificant. Only one study conducted an economic evaluation of the intervention and found it to be cost-effective when compared with the standard of care of no MSAT. We concluded that the evidence for implementing MSAT as part of a routine malaria control program is growing but limited. More research is necessary on its short- and longer-term impacts on clinical malaria and malaria transmission and its economic value.Food insecurity among households with children during the COVID-19 pandemic: results from a study among social media users across the United States
AbstractParekh, N., Ali, S. H., O’Connor, J., Tozan, Y., Jones, A. M., Capasso, A., Foreman, J., & DiClemente, R. J. (n.d.).Publication year
2021Journal title
Nutrition JournalVolume
20Issue
1AbstractBackground: In the United States, approximately 11% of households were food insecure prior to the COVID-19 pandemic. The present study aims to describe the prevalence of food insecurity among adults and households with children living in the United States during the pandemic. Methods: This study utilized social media as a recruitment platform to administer an original online survey on demographics and COVID-related food insecurity. The survey was disseminated through an advertisement campaign on Facebook and affiliated platforms. Food insecurity was assessed with a validated six-item United States Department of Agriculture (USDA) Household Food Security Survey Module, which was used to create a six-point numerical food security score, where a higher score indicates lower food security. Individual-level participant demographic information was also collected. Logistic regressions (low/very-low compared with high/marginal food security) were performed to generate adjusted odds ratios (AOR) and 95%CIs for food insecurity and select demographic characteristics. Results: Advertisements reached 250,701 individuals and resulted in 5,606 complete surveys. Overall, 14.7% of participants self-identified as having low or very low food security in their households, with higher prevalence (17.5%) among households with children. Unemployment (AOR:1.76, 95%CI:1.09–2.80), high school or lower education (AOR:2.25, 95%CI:1.29–3.90), and low income (AOR[$30,000-$50,000]:5.87, 95%CI:3.35–10.37; AOR[< $30,000]:10.61, 95%CI:5.50–20.80) were associated with higher odds of food insecurity in multivariable models among households with children (and the whole sample). Conclusions: These data indicate exacerbation of food insecurity during the pandemic. The study will be instrumental in guiding additional research and time-sensitive interventions targeted towards vulnerable food insecure subgroups.Household and hospitalization costs of pediatric dengue illness in Colombo, Sri Lanka
AbstractFernando, E. S., Headley, T. Y., Tissera, H., Wilder-Smith, A., De Silva, A., & Tozan, Y. (n.d.).Publication year
2021Journal title
American Journal of Tropical Medicine and HygieneVolume
105Issue
1Page(s)
110-116AbstractDengue, a mosquito-borne viral infection that affects millions around the world, poses a substantial economic burden in endemic countries. We conducted a prospective costing study in hospitalized pediatric dengue patients at the Lady Ridgeway Hospital for Children (LRHC), a public pediatric hospital in Colombo district, Sri Lanka, to assess household out-of-pocket and hospitalization costs of dengue in pediatric patients during peak dengue transmission season. Between August and October 2013, we recruited 216 hospitalized patients (aged 0-3 years, 27%; 4-7 years, 29%; 8-12 years, 42%) who were clinically or laboratory diagnosed with dengue. Using 2013 US dollars, household out-of-pocket spending, on average, was US$59 (SD 49) per episode and increased with disease severity (DF, US$52; DHF/ DSS, US$78). Pediatric dengue patients received free-of-charge medical care during hospitalization at LRHC, and this places a high financial burden on hospitals. The direct medical cost of hospitalization was US$68 (SD 31.4) for DF episode, and US$122.7 (SD 65.2) for DHF/DSS episode. Yet a hospitalized dengue illness episode still accounted for 20% to 35% of household monthly income due to direct and indirect costs. Additionally, a majority of caregivers (70%) sought outpatient care before hospitalization, most of whom (81%) visited private health facilities. Our findings indicate that hospitalized pediatric dengue illness poses a nontrivial cost burden to households and healthcare systems, emphasizing the importance of preventing and controlling the transmission of dengue in endemic countries.Impact of COVID-19-related knowledge on protective behaviors: The moderating role of primary sources of information
AbstractKim, S., Capasso, A., Cook, S. H., Ali, S. H., Jones, A. M., Foreman, J., DiClemente, R. J., & Tozan, Y. (n.d.).Publication year
2021Journal title
PloS oneVolume
16Issue
11AbstractThis study assessed the modifying role of primary source of COVID-19 information in the association between knowledge and protective behaviors related to COVID-19 among adults living in the United States (US). Data was collected from 6,518 US adults through an online cross-sectional self-administered survey via social media platforms in April 2020. Linear regression was performed on COVID-19 knowledge and behavior scores, adjusted for sociodemographic factors. An interaction term between knowledge score and primary information source was included to observe effect modification by primary information source. Higher levels of knowledge were associated with increased self-reported engagement with protective behaviors against COVID-19. The primary information source significantly moderated the association between knowledge and behavior, and analyses of simple slopes revealed significant differences by primary information source. This study shows the important role of COVID-19 information sources in affecting people's engagement in recommended protective behaviors. Governments and health agencies should monitor the use of various information sources to effectively engage the public and translate knowledge into behavior change during an evolving public health crisis like COVID-19.Improving child and adolescent mental health in Africa
AbstractTozan, Y., & Capasso, A. (n.d.). In Child Behavioral Health in Sub-Saharan Africa: A review of the economic evidence (1–).Publication year
2021Page(s)
41-65AbstractEvidence suggests that the burden of mental health problems among children and adolescents in Africa is significant, and that the treatment gap in mental health is widening. African countries have experienced considerable political and social instability and change and currently have the highest rates of HIV/AIDS and malaria in the world, which can result in neuropsychiatric sequelae. Yet, these countries have very few human and economic resources dedicated to the mental health of children and young people. This chapter reviews the state of the economic evidence base on mental health programs and interventions for children and adolescents in low-resource settings and examines the most immediate economic considerations of introducing, integrating, and scaling up these interventions to improve child and adolescent mental health and well-being in such settings.Increased alcohol use during the COVID-19 pandemic: The effect of mental health and age in a cross-sectional sample of social media users in the U.S.
AbstractCapasso, A., Jones, A. M., Ali, S. H., Foreman, J., Tozan, Y., & DiClemente, R. J. (n.d.).Publication year
2021Journal title
Preventive MedicineVolume
145AbstractThe COVID-19 pandemic has triggered a public health crisis of unprecedented scale. Increased alcohol use has been extensively documented during other crises, particularly among persons with anxiety and depression. Despite COVID-19's differential impact by age, the association of age, mental health and alcohol use during the pandemic has not been explored. This study aimed to examine whether age modified the association of anxiety and depressive symptoms with alcohol use during the COVID-19 pandemic. Two online surveys were administered to U.S. adult social media users in March and April 2020. Generalized linear models were conducted in 2020 among 5850 respondents (52.9% female; 22.0% aged 18–39 years, 47.0% aged 40–59 years, and 31.0% aged ≥60 years) to examine if age modified the association of anxiety and depression symptomatology and alcohol use. Overall, 29% of respondents reported increased alcohol use. Adjusted odds ratios of reporting increased alcohol use were 1.41 (95% CI = 1.20–1.66) among respondents with anxiety symptoms and 1.64 (95% CI = 1.21–2.23) among those with depressive symptoms compared to those without such symptoms. Whereas respondents aged 18–39 years had the highest probability of reporting increased alcohol use, the probability of older persons (40–59 and ≥60 years) reporting increased drinking was much greater among those with symptoms of anxiety and depression, compared to those without symptoms. These findings warrant age-differentiated public health messaging on the risks of excessive alcohol use and scale-up of substance use services for middle-aged and older adults with symptoms of depression and anxiety.Predictors of Depressive Symptoms and Post Traumatic Stress Disorder Among Women Engaged in Commercial Sex Work in Southern Uganda
AbstractNabunya, P., Byansi, W., Damulira, C., Bahar, O. S., Jennings Mayo-Wilson, L., Tozan, Y., Kiyingi, J., Nabayinda, J., Braithwaite, R., Witte, S. S., & Ssewamala, F. M. (n.d.).Publication year
2021Journal title
Psychiatry ResearchVolume
298AbstractThis study examined the factors associated with depressive symptoms and post traumatic depressive disorder (PTSD) among economically vulnerable women engaged in commercial sex work (WESW) in southern Uganda. Baseline data from a longitudinal cluster randomized study involving 542 self-identified WESW (18-55 years), recruited from 19 HIV hotspots were analyzed. Hierarchical linear regression modelling was utilized to estimate individual, family-level and economic-level predictors of depressive symptoms and PTSD. Family cohesion, sex work stigma, HIV status, financial distress, household assets, number of children and number of household income earners, were associated with PTSD. Similarly, family cohesion, number of people in the household, HIV status, sex work stigma, financial distress, and household assets, were associated with depressive symptoms. Women engaged in commercial sex work are at a higher risk of HIV and poor mental health outcomes. Sex work stigma and financial distress elevate levels of depressive symptoms and PTSD, over and above an individual's HIV status. Family and economic-level factors have the potential to mitigate the risk of poor mental health outcomes. As such, integrating stigma reduction and economic strengthening components in the programming targeting WESW—a key population, may be critical to address their mental health outcomes.Regional and socioeconomic predictors of perceived ability to access coronavirus testing in the United States: results from a nationwide online COVID-19 survey
AbstractAli, S. H., Tozan, Y., Jones, A. M., Foreman, J., Capasso, A., & DiClemente, R. J. (n.d.).Publication year
2021Journal title
Annals of EpidemiologyVolume
58Page(s)
7-14AbstractPurpose: Access to COVID-19 testing remained a salient issue during the early months of the pandemic, therefore this study aimed to identify 1) regional and 2) socioeconomic predictors of perceived ability to access Coronavirus testing. Methods: An online survey using social media-based advertising was conducted among U.S. adults in April 2020. Participants were asked whether they thought they could acquire a COVID-19 test, along with basic demographic, socioeconomic and geographic information. Results: A total of 6,378 participants provided data on perceived access to COVID-19 testing. In adjusted analyses, we found higher income and possession of health insurance to be associated with perceived ability to access Coronavirus testing. Geographically, perceived access was highest (68%) in East South Central division and lowest (39%) in West North Central. Disparities in health insurance coverage did not directly correspond to disparities in perceived access to COVID-19 testing. Conclusions: Sex, geographic location, income, and insurance status were associated with perceived access to COVID-19 testing; interventions aimed at improving either access or awareness of measures taken to improve access are warranted. These findings from the pandemic's early months shed light on the importance of disaggregating perceived and true access to screening during such crises.The effectiveness of malaria camps as part of the Durgama Anchalare Malaria Nirakaran (DAMaN) program in Odisha, India: study protocol for a cluster-assigned quasi-experimental study
AbstractOmpad, D. C., Kessler, A., Van Eijk, A. M., Padhan, T. K., Haque, M. A., Sullivan, S. A., Tozan, Y., Rocklöv, J., Mohanty, S., Pradhan, M. M., Sahu, P. K., & Carlton, J. M. (n.d.).Publication year
2021Journal title
Global Health ActionVolume
14Issue
1AbstractThe Indian state of Odisha has a longstanding battle with forest malaria. Many remote and rural villages have poor access to health care, a problem that is exacerbated during the rainy season when malaria transmission is at its peak. Approximately 62% of the rural population consists of tribal groups who are among the communities most negatively impacted by malaria. To address the persistently high rates of malaria in these remote regions, the Odisha State Malaria Control Program introduced ‘malaria camps’ in 2017 where teams of health workers visit villages to educate the population, enhance vector control methods, and perform village-wide screening and treatment. Malaria rates declined statewide, particularly in forested areas, following the introduction of the malaria camps, but the impact of the intervention is yet to be externally evaluated. This study protocol describes a cluster-assigned quasi-experimental stepped-wedge study with a pretest-posttest control group design that evaluates if malaria camps reduce the prevalence of malaria, compared to control villages which receive the usual malaria control interventions (e.g. IRS, ITNs), as detected by PCR.The efficacy and cost-effectiveness of a family-based economic empowerment intervention (Suubi + Adherence) on suppression of HIV viral loads among adolescents living with HIV: results from a Cluster Randomized Controlled Trial in southern Uganda
AbstractTozan, Y., Capasso, A., Sun, S., Neilands, T. B., Damulira, C., Namuwonge, F., Nakigozi, G., Mwebembezi, A., Mukasa, B., Sensoy Bahar, O., Nabunya, P., Mellins, C. A., McKay, M. M., & Ssewamala, F. M. (n.d.).Publication year
2021Journal title
Journal of the International AIDS SocietyVolume
24Issue
6AbstractIntroduction: Evidence from low-resource settings indicates that economic insecurity is a major barrier to HIV treatment adherence. Economic empowerment (EE) interventions have the potential to improve adherence outcomes among adolescents living with HIV (ALWHIV) by mitigating the effects of poverty. This study aims to assess the efficacy and cost-effectiveness of a savings-led family-based EE intervention, Suubi + Adherence, aimed at improving antiretroviral therapy (ART) adherence outcomes ALWHIV in Uganda. Methods: Adolescents (mean age 12 years at enrolment; 56% female) receiving ART for HIV at 39 health centres were randomized to Suubi + Adherence intervention (n = 358) or bolstered standard of care (BSOC; n = 344). A difference-in-differences analysis was employed to assess the change in the proportion of virally suppressed adolescents (HIV RNA viral load <40 copies/mL) over 24 months. The cost-effectiveness analysis examined how much the intervention cost to virally suppress one additional adolescent relative to BSOC from the healthcare provider perspective. Results: At 24 months, the intervention was associated with an 8.85-percentage point [95% confidence interval (CI) 0.80 to 16.90 percentage points] increase in the proportion of virally suppressed adolescents between the study arms (p = 0.032). Per-participant costs were US$177 and US$263 for the BSOC and intervention groups respectively. The incremental cost of virally suppressing one additional adolescent was estimated at US$970 [95% CI, US$508 to 10,725] over two years. Conclusions: Our results support the integration of family-based EE interventions into adherence-support strategies as part of routine HIV care in low-resource settings to address the underlying economic drivers of poor ART adherence among ALWHIV. Moreover, per-participant costs to achieve viral suppression do not seem prohibitive compared to other community-based adherence interventions targeted at ALWHIV in low-resource settings. Further research on combination interventions at the nexus of economic security and HIV treatment and care is needed to inform the development of feasible and scalable HIV policies and programmes.Reviewing estimates of the basic reproduction number for dengue, Zika and chikungunya across global climate zones
AbstractLiu, Y., Lillepold, K., Semenza, J. C., Tozan, Y., Quam, M. B., & Rocklöv, J. (n.d.).Publication year
2020Journal title
Environmental ResearchVolume
182AbstractBackground: Globally, dengue, Zika virus, and chikungunya are important viral mosquito-borne diseases that infect millions of people annually. Their geographic range includes not only tropical areas but also sub-tropical and temperate zones such as Japan and Italy. The relative severity of these arboviral disease outbreaks can vary depending on the setting. In this study we explore variation in the epidemiologic potential of outbreaks amongst these climatic zones and arboviruses in order to elucidate potential reasons behind such differences. Methodology: We reviewed the peer-reviewed literature (PubMed) to obtain basic reproduction number (R0) estimates for dengue, Zika virus, and chikungunya from tropical, sub-tropical and temperate regions. We also computed R0 estimates for temperate and sub-tropical climate zones, based on the outbreak curves in the initial outbreak phase. Lastly we compared these estimates across climate zones, defined by latitude. Results: Of 2115 studies, we reviewed the full text of 128 studies and included 65 studies in our analysis. Our results suggest that the R0 of an arboviral outbreak depends on climate zone, with lower R0 estimates, on average, in temperate zones (R0 = 2.03) compared to tropical (R0 = 3.44) and sub-tropical zones (R0 = 10.29). The variation in R0 was considerable, ranging from 0.16 to 65. The largest R0 was for dengue (65) and was estimated by the Ross-Macdonald model in the tropical zone, whereas the smallest R0 (0.16) was for Zika virus and was estimated statistically from an outbreak curve in the sub-tropical zone. Conclusions: The results indicate climate zone to be an important determinant of the basic reproduction number, R0, for dengue, Zika virus, and chikungunya. The role of other factors as determinants of R0, such as methods, environmental and social conditions, and disease control, should be further investigated. The results suggest that R0 may increase in temperate regions in response to global warming, and highlight the increasing need for strengthening preparedness and control activities.Severe dengue epidemic, Sri Lanka, 2017
AbstractTissera, H. A., Jayamanne, B. D., Raut, R., Janaki, S. M., Tozan, Y., Samaraweera, P. C., Liyanage, P., Ghouse, A., Rodrigo, C., De Silva, A. M., & Fernando, S. D. (n.d.).Publication year
2020Journal title
Emerging Infectious DiseasesVolume
26Issue
4Page(s)
682-691AbstractIn 2017, a dengue epidemic of unexpected magnitude occurred in Sri Lanka. A total of 186,101 suspected cases and 440 dengue-related deaths occurred. We conducted a comprehensive analysis of this epidemic by comparing national surveillance data for 2017 with data from the preceding 5 years. In all Sri Lanka districts, dengue incidence in 2017 increased significantly over incidence during the previous 5 years. Older schoolchildren and young adults were more clinically symptomatic than those at extremes of age. Limited virologic surveillance showed the dominant circulating variant was dengue virus type 2 cosmopolitan genotype in the most affected district. One quarter of total annual cases were reported 5 weeks after the southwest monsoon started. Changes in vector abundance were not predictive of the increased incidence. Direct government expenditures on dengue control activities in 2017 were US $12.7 million. The lessons learned from this outbreak are useful for other tropical nations facing increasing dengue incidence.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 analysis
AbstractAli, S. H., Foreman, J., Capasso, A., Jones, A. M., Tozan, Y., & Diclemente, R. J. (n.d.).Publication year
2020Journal title
BMC Medical Research MethodologyVolume
20Issue
1AbstractBACKGROUND: 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 $0.09 per click and $0.18 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
AbstractDiSera, L., Sjödin, H., Rocklöv, J., Tozan, Y., Súdre, B., Zeller, H., & Muñoz, Ángel G. (n.d.).Publication year
2020Journal title
GeoHealthVolume
4Issue
8AbstractThe 2018 outbreak of dengue in the French overseas department of Réunion was unprecedented in size and spread across the island. This research focuses on the cause of the outbreak, asserting that climate played a large role in the proliferation of the Aedes albopictus mosquitoes, which transmitted the disease, and led to the dengue outbreak in early 2018. A stage-structured model was run using observed temperature and rainfall data to simulate the life cycle and abundance of the Ae. albopictus mosquito. Further, the model was forced with bias-corrected subseasonal forecasts to determine if the event could have been forecast up to 4 weeks in advance. With unseasonably warm temperatures remaining above 25°C, along with large tropical-cyclone-related rainfall events accumulating 10–15 mm per event, the modeled Ae. albopictus mosquito abundance did not decrease during the second half of 2017, contrary to the normal behavior, likely contributing to the large dengue outbreak in early 2018. Although subseasonal forecasts of rainfall for the December–January period in Réunion are skillful up to 4 weeks in advance, the outbreak could only have been forecast 2 weeks in advance, which along with seasonal forecast information could have provided enough time to enhance preparedness measures. Our research demonstrates the potential of using state-of-the-art subseasonal climate forecasts to produce actionable subseasonal dengue predictions. To the best of the authors' knowledge, this is the first time subseasonal forecasts have been used this way.Transmission dynamics of dengue and chikungunya in a changing climate: do we understand the eco-evolutionary response?
AbstractTozan, Y., Sjödin, H., Muñoz, Ángel G., & Rocklöv, J. (n.d.).Publication year
2020Journal title
Expert Review of Anti-Infective TherapyVolume
18Issue
12Page(s)
1187-1193AbstractIntroduction: We are witnessing an alarming increase in the burden and range of mosquito-borne arboviral diseases. The transmission dynamics of arboviral diseases is highly sensitive to climate and weather and is further affected by non-climatic factors such as human mobility, urbanization, and disease control. As evidence also suggests, climate-driven changes in species interactions may trigger evolutionary responses in both vectors and pathogens with important consequences for disease transmission patterns. Areas covered: Focusing on dengue and chikungunya, we review the current knowledge and challenges in our understanding of disease risk in a rapidly changing climate. We identify the most critical research gaps that limit the predictive skill of arbovirus risk models and the development of early warning systems, and conclude by highlighting the potentially important research directions to stimulate progress in this field. Expert opinion: Future studies that aim to predict the risk of arboviral diseases need to consider the interactions between climate modes at different timescales, the effects of the many non-climatic drivers, as well as the potential for climate-driven adaptation and evolution in vectors and pathogens. An important outcome of such studies would be an enhanced ability to promulgate early warning information, initiate adequate response, and enhance preparedness capacity.Trends and predictors of COVID-19 information sources and their relationship with knowledge and beliefs related to the pandemic: Nationwide cross-sectional study
AbstractAli, S. H., Foreman, J., Tozan, Y., Capasso, A., Jones, A. M., & DiClemente, R. J. (n.d.).Publication year
2020Journal title
JMIR Public Health and SurveillanceVolume
6Issue
4AbstractBackground: 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
AbstractSsewamala, F. M., Sensoy Bahar, O., Tozan, Y., Nabunya, P., Mayo-Wilson, L. J., Kiyingi, J., Kagaayi, J., Bellamy, S., McKay, M. M., & Witte, S. S. (n.d.).Publication year
2019Journal title
BMC Women's HealthVolume
19Issue
1AbstractBackground: Sub-Saharan Africa (SSA) has the highest number of people living with HIV/AIDS, with Nigeria, South Africa, and Uganda accounting for 48% of new infections. A systematic review of the HIV burden among women engaged in sex work (WESW) in 50 low- and middle-income countries found that they had increased odds of HIV infection relative to the general female population. Social structural factors, such as the sex work environment, violence, stigma, cultural issues, and criminalization of sex work are critical in shaping sexually transmitted infection (STI)/HIV risks among WESW and their clients in Uganda. Poverty is the most commonly cited reason for involvement in sex work in SSA. Against this backdrop, this study protocol describes a randomized controlled trial (RCT) that tests the impact of adding economic empowerment to traditional HIV risk reduction (HIVRR) to reduce new incidence of STIs and HIV among WESW in Rakai and the greater Masaka regions in Uganda. Methods: This three-arm RCT will evaluate the efficacy of adding savings, financial literacy and vocational training/mentorship to traditional HIVRR on reducing new incidence of STI infections among 990 WESW across 33 hotspots. The three arms (n = 330 each) are: 1) Control group: only HIVRR versus 2) Treatment group 1: HIVRR plus Savings plus Financial Literacy (HIVRR + S + FL); and 3) Treatment group 2: HIVRR plus S plus FL plus Vocational Skills Training and Mentorship (V) (HIVRR + S + FL + V). Data will be collected at baseline (pre-test), 6, 12, 18 and 24-months post-intervention initiation. This study will use an embedded experimental mixed methods design where qualitative data will be collected post-intervention across all conditions to explore participant experiences. Discussion: When WESW have access to more capital and/or alternative forms of employment and start earning formal income outside of sex work, they may be better able to improve their skills and employability for professional advancement, thereby reducing their STI/HIV risk. The study findings may advance our understanding of how best to implement gender-specific HIV prevention globally, engaging women across the HIV treatment cascade. Further, results will provide evidence for the intervention's efficacy to reduce STIs and inform implementation sustainability, including costs and cost-effectiveness. Trial registration: ClinicalTrials.gov, ID: NCT03583541.A combination of incidence data and mobility proxies from social media predicts the intraurban spread of dengue in Yogyakarta, Indonesia
AbstractRamadona, A. L., Tozan, Y., Lazuardi, L., & Rocklöv, J. (n.d.).Publication year
2019Journal title
PLoS neglected tropical diseasesVolume
13Issue
4AbstractOnly a few studies have investigated the potential of using geotagged social media data for predicting the patterns of spatio-temporal spread of vector-borne diseases. We herein demonstrated the role of human mobility in the intra-urban spread of dengue by weighting local incidence data with geo-tagged Twitter data as a proxy for human mobility across 45 neighborhoods in Yogyakarta city, Indonesia. To estimate the dengue virus importation pressure in each study neighborhood monthly, we developed an algorithm to estimate a dynamic mobility- weighted incidence index (MI), which quantifies the level of exposure to virus importation in any given neighborhood. Using a Bayesian spatio-temporal regression model, we estimated the coefficients and predictiveness of the MI index for lags up to 6 months. Specifically, we used a Poisson regression model with an unstructured spatial covariance matrix. We compared the predictability of the MI index to that of the dengue incidence rate over the preceding months in the same neighborhood (autocorrelation) and that of the mobility information alone. We based our estimates on a volume of 1.302.405 geotagged tweets (from 118.114 unique users) and monthly dengue incidence data for the 45 study neighborhoods in Yogyakarta city over the period from August 2016 to June 2018. The MI index, as a standalone variable, had the highest explanatory power for predicting dengue transmission risk in the study neighborhoods, with the greatest predictive ability at a 3-months lead time. The MI index was a better predictor of the dengue risk in a neighborhood than the recent transmission patterns in the same neighborhood, or just the mobility patterns between neighborhoods. Our results suggest that human mobility is an important driver of the spread of dengue within cities when combined with information on local circulation of the dengue virus. The geotagged Twitter data can provide important information on human mobility patterns to improve our understanding of the direction and the risk of spread of diseases, such as dengue. The proposed MI index together with traditional data sources can provide useful information for the development of more accurate and efficient early warning and response systems.