Yesim Tozan

Yesim Tozan
Yesim Tozan
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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, Turkey
MS, Environmental Technology, Bogazici University, Turkey
MA, Public Affairs, Princeton University, Princeton, NJ
PhD, Public Affairs, Princeton University, Princeton, NJ

Areas of research and study

Cost Effectiveness
Cost-effective Health Programs and Policies
Economic Evaluation
Health Economics
Infectious Diseases
Prevention Interventions

Publications

Publications

A pre-post evaluation study of a social media-based COVID-19 communication campaign to improve attitudes and behaviors toward COVID-19 vaccination in Tanzania

Kim, S., Lilani, A., Redemptus, C., Campana, K., & Tozan, Y. (n.d.).

Publication year

2024

Journal title

PloS one

Volume

19

Issue

5
Abstract
Abstract
In Tanzania, the One by One: Target COVID-19 campaign was launched nationally in July 2022 to address the prevalent vaccine hesitancy and lack of confidence in COVID-19 vaccines. The campaign mobilized social media influencers and viral content with the ultimate goal of increasing COVID-19 vaccine uptake in the country. The objective of this study was to empirically assess the impact of the campaign on three outcomes: vaccine confidence, vaccine hesitancy, and vaccination status. Using programmatic data collected through an online survey before and after the campaign, we conducted a difference-in-difference (DiD) analysis and performed a crude, adjusted, and propensity score-matched analysis for each study outcome. Lastly, to observe whether there was any differential impact of the campaign across age groups, we repeated the analyses on age-stratified subgroups. Data included 5,804 survey responses, with 3,442 and 2,362 responses collected before and after the campaign, respectively. Although there was only weak evidence of increased COVID-19 vaccine confidence in the campaign-exposed group compared to the control group across all age groups, we observed a differential impact among different age groups. While no significant change was observed among young adults aged 18–24 years, the campaign exposure led to a statistically significant increase in vaccine confidence (weighted/adjusted DiD coefficient = 0.76; 95% CI: 0.06, 1.5; p-value = 0.034) and vaccination uptake (weighted/adjusted DiD coefficient = 1.69.; 95% CI: 1.02, 2.81; p-value = 0.023) among young adults aged 25–34 years. Among adults aged 35 years and above, the campaign exposure led to a significant decrease in vaccine hesitancy (weighted/adjusted DiD coefficient = -15; 95% CI: -21, -8.3; p-value<0.001). The social media campaign successfully improved vaccine hesitancy, confidence, and uptake in the Tanzanian population, albeit to varying degrees across age groups. Our study provides valuable insights for the planning and evaluation of similar social media communication campaigns aiming to bolster vaccination efforts.

Childhood Violence, High School Academic Environment, and Adult Alcohol Use Among Latinas and Black Women: A Structural Equation Modeling Study

Capasso, A., Tozan, Y., DiClemente, R. J., & Pahl, K. (n.d.).

Publication year

2024

Journal title

Journal of Interpersonal Violence
Abstract
Abstract
Objective: Young Latinas and Black women drink less than women of other racial/ethnic groups but experience more alcohol-related problems in midlife. This study aims to identify modifiable factors to prevent adult onset of alcohol use disorder (AUD) in this population. Methods: Data were collected at six time points as part of the Harlem Longitudinal Development Study from 365 Latinas (47%) and Black (53%) women (mean age at time 1 = 14, standard deviation 1.3). Structural equation modeling was used to test hypothesized pathways from childhood physical and sexual abuse to AUD via depressive mood, anxiety disorders, and somatic complaints in the 20s. We also tested the moderation effect of the high school academic environment by including in the structural equation model two latent variable interaction terms between the school environment and each of the abuse variables. Results: Childhood physical and sexual abuse was positively associated with depressive mood, anxiety disorders, and somatic complaints when participants were in the 20s. Depressive mood mediated childhood abuse and AUD when women were in the 30s. The high school academic environment attenuated the effect of physical, but not sexual abuse, on depressive mood (β = −0.59, B = −9.38, 95% CI [−14.00, −4.76]), anxiety symptoms (β = −0.61, B = −14.19, 95% CI [−21.76, −6.61]), appetite loss (β = −0.41, B = −10.52, 95% CI [−15.61, −5.42]), and sleeplessness (β = −0.50, B = −9.56, 95% CI [−13.95, −5.17]) in the early 20s. Conclusions: Our findings underscore the need to invest in early violence prevention interventions and in education to ensure equitable access to quality, academically oriented, and safe schools.

Costing of a Combination Intervention (Kyaterekera) Addressing Sexual Risk-Taking Behaviors among Vulnerable Women in Southern Uganda

Tozan, Y., Kiyingi, J., Kim, S., Nabayinda, J., Namuwonge, F., Nsubuga, E., Nakabuye, F., Sensoy, O. B., Nabunya, P., Mayo-Wilson, L. J., McKay, M. M., Witte, S. S., & Ssewamala, F. M. (n.d.).

Publication year

2024

Journal title

American Journal of Tropical Medicine and Hygiene

Volume

110

Issue

5

Page(s)

1046-1056
Abstract
Abstract
In Uganda, women engaged in sex work (WESW) are a marginalized population at the intersection of multiple vulnerabilities. The Kyaterekera intervention is targeted at WESW in Rakai and the greater Masaka regions in Uganda and combines a traditional HIV risk-reduction approach with a savings-led economic empowerment intervention and financial literacy training. We estimated the economic costs of the Kyaterekera intervention from a program provider perspective using a prospective activity-based micro-costing method. All program activities and resource uses were measured and valued across the control arm receiving a traditional HIV risk-reduction intervention and the treatment arm receiving a matched individual development savings account and financial literacy training on top of HIV risk reduction. The total per-participant cost by arm was adjusted for inflation and discounted at an annual rate of 3% and presented in 2019 US dollars. The total per-participant costs of the control and intervention arms were estimated at $323 and $1,435, respectively, using the per-protocol sample. When calculated based on the intent-to-treat sample, the per-participant costs were reduced to $183 and $588, respectively. The key cost drivers were the capital invested in individual development accounts and personnel and transportation costs for program operations, linked to WESW's higher mobility and the dispersed pattern of hot spot locations. The findings provide evidence of the economic costs of implementing a targeted intervention for this marginalized population in resource-constrained settings and shed light on the scale of potential investment needed to better achieve the health equity goal of HIV prevention strategies.

The synergistic impact of Universal Health Coverage and Global Health Security on health service delivery during the Coronavirus Disease-19 pandemic: A difference-indifference study of childhood immunization coverage from 192 countries

Kim, S., Headley, T. Y., & Tozan, Y. (n.d.).

Publication year

2024

Journal title

PLOS global public health

Volume

4

Issue

5
Abstract
Abstract
Universal Health Coverage (UHC) and Global Health Security (GHS) are two high-priority global health agendas that seek to foster health system resilience against health emergencies. Many countries have had to prioritize one agenda over the other due to scarce resources and political pressures. To aid policymakers’ decision-making, this study investigated the individual and synergistic effects of countries’ UHC and GHS capacities in safeguarding essential health service delivery during the COVID-19 pandemic. We used a quasi-experimental difference-in-difference methodology to quantify the relationship between 192 countries’ progress towards UHC and GHS and those countries’ abilities to provide 12 essential childhood immunization services between 2015 and 2021. We used the 2019 UHC Service Coverage Index (SCI) to divide countries into a “high UHC group” (UHC SCI≥75) and the rest (UHC SCI 75), and similarly used the 2019 GHS Index (GHSI) to divide countries into a “high GHS group” (GHSI≥65) and the rest (GHSI<65). All analyses were adjusted for potential confounders. Countries with high UHC scores prevented a 1.14% (95% CI: 0.39%, 1.90%) reduction in immunization coverage across 2020 and 2021 whereas countries with high GHSI scores prevented a 1.10% (95% CI: 0.57%, 1.63%) reduction in immunization coverage over the same time period. The stratified DiD models showed that across both years, high UHC capacity needed to be augmented with high GHS capacity to prevent a decline in immunization coverage while high GHS alone was able to safeguard immunization coverage. This study found that greater progress towards both UHC and GHS capacities safeguarded essential health service delivery during the pandemic but only progress towards GHS capacity was both a necessary and likely sufficient element for yielding this protective effect. Our results call for strategic investments into both health agendas and future research into possible synergistic effects of the two health agendas.

Understanding COVID-19 vaccine hesitancy in Meghalaya, India: Multiple correspondence and agglomerative hierarchical cluster analyses

Kim, S., Sarkar, R., Kumar, S., Lewis, M. G., Tozan, Y., & Albert, S. (n.d.).

Publication year

2024

Journal title

PLOS global public health

Volume

4

Issue

2
Abstract
Abstract
Meghalaya, a state in the northeastern region of India, had a markedly low vaccine uptake compared to the other states in the country when COVID-19 vaccines were being rolled out in 2021. This study aimed to characterize the distinct vaccine-hesitant subpopulations in healthcare and community settings in Meghalaya state in the early days of the vaccination program. We used data from a cross-sectional survey that was administered to 200 healthcare workers (HCWs) and 200 community members, who were a priori identified as 'vaccine- eligible' and 'vaccine-hesitant,' in Shillong city, Meghalaya, in May 2021. The questionnaire collected information on participants' sociodemographic characteristics, COVID-19 history, and presence of medical comorbidities. Participants were also asked to provide a dichotomous answer to a set of 19 questions, probing the reasons for their hesitancy towards COVID-19 vaccines. A multiple correspondence analysis, followed by an agglomerative hierarchical cluster analysis, was performed to identify the distinct clusters of vaccine-hesitant participants. We identified seven clusters: indecisive HCWs (n = 71), HCWs skeptical of COVID-19 and COVID-19 vaccines (n = 128), highly educated male tribal/clan leaders concerned about infertility and future pregnancies (n = 14), less educated adults influenced by leaders and family (n = 47), older adults worried about vaccine safety (n = 76), middle-aged adults without young children (n = 56), and highly educated ethnic/religious minorities with misinformation (n = 8). Across all the clusters, perceived logistical challenges associated with receiving the vaccine was identified as a common factor contributing to vaccine hesitancy. Our study findings provide valuable insights for local and state health authorities to effectively target distinct subgroups of vaccine-hesitant populations with tailored health messaging, and also call for a comprehensive approach to address the common drivers of vaccine hesitancy in communities with low vaccination rates.

"I decided in my heart I have to complete the sessions": A qualitative study on the acceptability of an evidence-based HIV risk reduction intervention among women engaged in sex work in Uganda

Bahar, O. S., Nabunya, P., Nabayinda, J., Witte, S., Kiyingi, J., Nsubuga, E., Schriger, S., Nattabi, J., Mayo-Wilson, L. J., Nakigudde, J., Tozan, Y., & Ssewamala, F. M. (n.d.).

Publication year

2023

Journal title

PloS one

Volume

18

Issue

1
Abstract
Abstract
Background The HIV burden remains a critical public health concern and women engaged in sex work [WESW] are at significantly higher risk compared to the general adult population. Similar to other sub-Saharan African countries, Uganda reports high rates of HIV prevalence among WESW. Yet, they have not been targeted by theory-informed HIV prevention intervention approaches. Methods We conducted semi-structured in-depth interviews with 20 WESW upon intervention completion to explore their experiences with an evidence-based HIV risk reduction intervention that was implemented as part of a combination intervention tested in a clinical trial in Uganda (2018-2023. Specifically, we explored their initial motivations and concerns for participating in the intervention, barriers and facilitators to attendance, and their feedback on specific intervention characteristics. Results The main expectations revolved around access to health-related information, including information on STIs, HIV, and PrEP as well as on how one can protect themselves while engaging in sex work. Initial concerns were around potential breach of confidentiality and fear of arrest. The main facilitators for session attendance were the motivation to learn healthrelated information, the attitude of facilitators, and the incentives received for participation, whereas main challenges were related to family commitments and work schedules. WESW appreciated the group format of the intervention and found the location and times of the intervention delivery acceptable. Discussion and conclusions Overall, our findings suggest that the HIV risk reduction intervention was appropriate and acceptable to WESW. Yet, WESW experience unique concerns and barriers that need to be accounted for when designing interventions targeting this population, especially in resource-limited settings where sex work is illegal and highly stigmatized.

A Methodological Framework for Economic Evaluation of Operational Response to Vector-Borne Diseases Based on Early Warning Systems

Tozan, Y., Sewe, M. O., Kim, S., & Rocklov, J. (n.d.).

Publication year

2023

Journal title

American Journal of Tropical Medicine and Hygiene

Volume

108

Issue

3

Page(s)

627-633
Abstract
Abstract
Despite significant advances in improving the predictive models for vector-borne diseases, only a few countries have integrated an early warning system (EWS) with predictive and response capabilities into their disease surveillance systems. The limited understanding of forecast performance and uncertainties by decision-makers is one of the primary factors that precludes its operationalization in preparedness and response planning. Further, predictive models exhibit a decrease in forecast skill with longer lead times, a trade-off between forecast accuracy and timeliness and effectiveness of action. This study presents a methodological framework to evaluate the economic value of EWS-triggered responses from the health system perspective. Assuming an operational EWS in place, the framework makes explicit the trade-offs between forecast accuracy, timeliness of action, effectiveness of response, and costs, and uses the net benefit analysis, which measures the benefits of taking action minus the associated costs. Uncertainty in disease forecasts and other parameters is accounted for through probabilistic sensitivity analysis. The output is the probability distribution of the net benefit estimates at given forecast lead times. A non-negative net benefit and the probability of yielding such are considered a general signal that the EWS-triggered response at a given lead time is economically viable. In summary, the proposed framework translates uncertainties associated with disease forecasts and other parameters into decision uncertainty by quantifying the economic risk associated with operational response to vector-borne disease events of potential importance predicted by an EWS. The goal is to facilitate a more informed and transparent public health decision-making under uncertainty.

Climate variability, socio-economic conditions and vulnerability to malaria infections in Mozambique 2016–2018: a spatial temporal analysis

Armando, C. J., Rocklöv, J., Sidat, M., Tozan, Y., Mavume, A. F., Bunker, A., & Sewes, M. O. (n.d.).

Publication year

2023

Journal title

Frontiers in Public Health

Volume

11
Abstract
Abstract
Background: Temperature, precipitation, relative humidity (RH), and Normalized Different Vegetation Index (NDVI), influence malaria transmission dynamics. However, an understanding of interactions between socioeconomic indicators, environmental factors and malaria incidence can help design interventions to alleviate the high burden of malaria infections on vulnerable populations. Our study thus aimed to investigate the socioeconomic and climatological factors influencing spatial and temporal variability of malaria infections in Mozambique. Methods: We used monthly malaria cases from 2016 to 2018 at the district level. We developed an hierarchical spatial–temporal model in a Bayesian framework. Monthly malaria cases were assumed to follow a negative binomial distribution. We used integrated nested Laplace approximation (INLA) in R for Bayesian inference and distributed lag nonlinear modeling (DLNM) framework to explore exposure-response relationships between climate variables and risk of malaria infection in Mozambique, while adjusting for socioeconomic factors. Results: A total of 19,948,295 malaria cases were reported between 2016 and 2018 in Mozambique. Malaria risk increased with higher monthly mean temperatures between 20 and 29°C, at mean temperature of 25°C, the risk of malaria was 3.45 times higher (RR 3.45 [95%CI: 2.37–5.03]). Malaria risk was greatest for NDVI above 0.22. The risk of malaria was 1.34 times higher (1.34 [1.01–1.79]) at monthly RH of 55%. Malaria risk reduced by 26.1%, for total monthly precipitation of 480 mm (0.739 [95%CI: 0.61–0.90]) at lag 2 months, while for lower total monthly precipitation of 10 mm, the risk of malaria was 1.87 times higher (1.87 [1.30–2.69]). After adjusting for climate variables, having lower level of education significantly increased malaria risk (1.034 [1.014–1.054]) and having electricity (0.979 [0.967–0.992]) and sharing toilet facilities (0.957 [0.924–0.991]) significantly reduced malaria risk. Conclusion: Our current study identified lag patterns and association between climate variables and malaria incidence in Mozambique. Extremes in climate variables were associated with an increased risk of malaria transmission, peaks in transmission were varied. Our findings provide insights for designing early warning, prevention, and control strategies to minimize seasonal malaria surges and associated infections in Mozambique a region where Malaria causes substantial burden from illness and deaths.

Correlates of Intimate Partner Violence Among Young Women Engaged in Sex Work in Southern Uganda

Nabayinda, J., Namirembe, R., Kizito, S., Nsubuga, E., Nabunya, P., Sensoy Bahar, O., Magorokosho, N., Kiyingi, J., Nattabi, J., Tozan, Y., Jennings Mayo-Wilson, L., Mwebembezi, A., Witte, S. S., & Ssewamala, F. M. (n.d.).

Publication year

2023

Journal title

Journal of Interpersonal Violence

Volume

38

Issue

19

Page(s)

10749-10770
Abstract
Abstract
Intimate partner violence (IPV) is a significant global public health problem that results in high social and economic costs to individuals and communities. Compared to women in the general population, women engaged in sex work (WESW) are more likely to experience physical, emotional, and sexual IPV. This study examines the correlates of IPV among young WESW with their intimate partners in Southern Uganda. We used baseline data from the Kyaterekera project, a 5 year NIH-funded longitudinal study aimed at reducing HIV risks among 542 WESW in Southern Uganda. To examine the factors associated with IPV, we fitted three separate multi-level Poisson regression models for physical, emotional, and sexual IPV, respectively. Average age was 31.4 years, and 54% of the women reported being victims of at least one form of IPV from their intimate partners. Model one assessed correlates of sexual IPV. Being married women (β =.71, 95% CI [0.24, 1.17]), divorced/separated/widowed (β =.52, [0.02, 1.02]), depressed (β =.04, [0.02, 0.05]), and having any sexually transmitted infections (STIs) (β =.58, [0.14, 1.01]) were associated with sexual IPV. Model two assessed correlates of physical IPV. Experience of childhood sexual abuse (β =.12, [0.04, 0.19]) was associated with an increase in physical IPV, and increasing age reduced its occurrence (β = −.02, [−0.04, −0.001]). Finally, model three assessed emotional IPV. Women with higher education (β =.49, [0.14, 0.85]) and symptoms of depression (β =.02, [0.001, 0.04]) had higher risks for emotional IPV. For WESW, IPV presents an additional potential pathway for HIV and STIs acquisition and transmission through a lack of negotiating power for safe sex. Efforts to reduce violence against WESW should be prioritized as a strategy for enhancing the well-being of WESW.

Economic Abuse and Care-seeking Practices for HIV and Financial Support Services in Women Employed by Sex Work: A Cross-Sectional Baseline Assessment of a Clinical Trial Cohort in Uganda

Jennings Mayo-Wilson, L., Yen, B. J., Nabunya, P., Bahar, O. S., Wright, B. N., Kiyingi, J., Filippone, P. L., Mwebembezi, A., Kagaayi, J., Tozan, Y., Nabayinda, J., Witte, S. S., & Ssewamala, F. M. (n.d.).

Publication year

2023

Journal title

Journal of Interpersonal Violence

Volume

38

Issue

1

Page(s)

NP1920-NP1949
Abstract
Abstract
Economic hardship is a driver of entry into sex work, which is associated with high HIV risk. Yet, little is known about economic abuse in women employed by sex work (WESW) and its relationship to uptake of HIV prevention and financial support services. This study used cross-sectional baseline data from a multisite, longitudinal clinical trial that tests the efficacy of adding economic empowerment to traditional HIV risk reduction education on HIV incidence in 542 WESW. Mixed effects logistic and linear regressions were used to examine associations in reported economic abuse by demographic characteristics, sexual behaviors, HIV care-seeking, and financial care-seeking. Mean age was 31.4 years. Most WESW were unmarried (74%) and had less than primary school education (64%). 48% had savings, and 72% had debt. 93% reported at least one economic abuse incident. Common incidents included being forced to ask for money (80%), having financial information kept from them (61%), and being forced to disclose how money was spent (56%). WESW also reported partners/relatives spending money needed for bills (45%), not paying bills (38%), threatening them to quit their job(s) (38%), and using physical violence when earning income (24%). Married/partnered WESW (OR = 2.68, 95% CI:1.60–4.48), those with debt (OR = 1.70, 95% CI:1.04–2.77), and those with sex-work bosses (OR = 1.90, 95% CI:1.07–3.38) had higher economic abuse. Condomless sex (β = +4.43, p <.05) was higher among WESW experiencing economic abuse, who also had lower odds of initiating PrEP (OR =.39, 95% CI:.17–.89). WESW experiencing economic abuse were also more likely to ask for cash among relatives (OR = 2.36, 95% CI:1.13–4.94) or banks (OR = 2.12, 95% CI:1.11–4.03). The high prevalence of HIV and economic abuse in WESW underscores the importance of integrating financial empowerment in HIV risk reduction interventions for WESW, including education about economic abuse and strategies to address it. Programs focusing on violence against women should also consider economic barriers to accessing HIV prevention services.

European projections of West Nile virus transmission under climate change scenarios

Farooq, Z., Sjödin, H., Semenza, J. C., Tozan, Y., Sewe, M. O., Wallin, J., & Rocklöv, J. (n.d.).

Publication year

2023

Journal title

One Health

Volume

16
Abstract
Abstract
West Nile virus (WNV), a mosquito-borne zoonosis, has emerged as a disease of public health concern in Europe. Recent outbreaks have been attributed to suitable climatic conditions for its vectors favoring transmission. However, to date, projections of the risk for WNV expansion under climate change scenarios is lacking. Here, we estimate the WNV-outbreaks risk for a set of climate change and socioeconomic scenarios. We delineate the potential risk-areas and estimate the growth in the population at risk (PAR). We used supervised machine learning classifier, XGBoost, to estimate the WNV-outbreak risk using an ensemble climate model and multi-scenario approach. The model was trained by collating climatic, socioeconomic, and reported WNV-infections data (2010−22) and the out-of-sample results (1950–2009, 2023–99) were validated using a novel Confidence-Based Performance Estimation (CBPE) method. Projections of area specific outbreak risk trends, and corresponding population at risk were estimated and compared across scenarios. Our results show up to 5-fold increase in West Nile virus (WNV) risk for 2040-60 in Europe, depending on geographical region and climate scenario, compared to 2000-20. The proportion of disease-reported European land areas could increase from 15% to 23-30%, putting 161 to 244 million people at risk. Across scenarios, Western Europe appears to be facing the largest increase in the outbreak risk of WNV. The increase in the risk is not linear but undergoes periods of sharp changes governed by climatic thresholds associated with ideal conditions for WNV vectors. The increased risk will require a targeted public health response to manage the expansion of WNV with climate change in Europe.

Examining Changes in Sleep Duration Associated with the Onset of the COVID-19 Pandemic: Who is Sleeping and Who is Not?

Batool-Anwar, S., Robbins, R., Ali, S. H., Capasso, A., Foreman, J., Jones, A. M., Tozan, Y., DiClemente, R. J., & Quan, S. F. (n.d.).

Publication year

2023

Journal title

Behavioral Medicine

Volume

49

Issue

2

Page(s)

162-171
Abstract
Abstract
The COVID-19 pandemic has resulted in social isolation and reports of insomnia. However, reports of changes in sleep duration and associated factors are few. To determine the impact of COVID-19 on changes in sleep behavior, data were analyzed from an online survey of adults recruited via social media that included questions asking whether the respondent slept less or more after the onset of the pandemic as well as self-reported sociodemographic and occupational information; beliefs about COVID-19; and responses pertaining to loneliness, anxiety, and depression. There were 5,175 respondents; 53.9% had a change in sleep duration.17.1% slept less and 36.7% slept more. Sleeping more was related to greater education, being single/divorced/separated, unemployed or a student. Being retired, divorced/separated or a homemaker, and living in the Mountain or Central time zones were associated with less sleep. Beliefs that COVID-19 would result in personal adverse consequences was associated with both more and less sleep. However, the strongest associations for both more and less sleep were seen with depression, anxiety, and loneliness. In summary, changes in sleep duration since the start of the COVID-19 pandemic were highly prevalent among social media users and were associated with several sociodemographic factors and beliefs that COVID-19 would have adverse personal impacts. However, the strongest associations occurred with worse mental health suggesting that improvements may occur with better sleep. Supplemental data for this article is available online at https://doi.org/10.1080/08964289.2021.2002800.

Impact, healthcare utilization and costs of travel-associated mosquito-borne diseases in international travellers: a prospective study

Tozan, Y., Headley, T. Y., Javelle, E., Gautret, P., Grobusch, M., De Pijper, C., Asgeirsson, H., Chen, L. H., Bourque, D., Menéndez, M. D., Moro, L., Gobbi, F., Sánchez-Montalvá, A., Connor, B. A., Matteelli, A., Crosato, V., Huits, R., Libman, M., & Hamer, D. H. (n.d.).

Publication year

2023

Journal title

Journal of Travel Medicine

Volume

30

Issue

7
Abstract
Abstract
Background: International travellers frequently acquire infectious diseases whilst travelling, yet relatively little is known about the impact and economic burden of these illnesses on travellers. We conducted a prospective exploratory costing study on adult returning travellers with falciparum malaria, dengue, chikungunya or Zika virus. Methods: Patients were recruited in eight Travel and Tropical Medicine clinics between June 2016 and March 2020 upon travellers’ first contact with the health system in their country of residence. The patients were presented with a structured 52-question self-administered questionnaire after full recovery to collect information on patients’ healthcare utilization and out-of-pocket costs both in the destination and home country, and about income and other financial losses due to the illness. Results: A total of 134 patients participated in the study (malaria, 66; dengue, 51; chikungunya, 8; Zika virus, 9; all fully recovered; median age 40; range 18–72 years). Prior to travelling, 42% of patients reported procuring medical evacuation insurance. Across the four illnesses, only 7% of patients were hospitalized abroad compared with 61% at home. Similarly, 15% sought ambulatory services whilst abroad compared with 61% at home. The average direct out-of-pocket hospitalization cost in the destination country (USD $2236; range: $108–$5160) was higher than the direct out-of-pocket ambulatory cost in the destination country (USD $327; range: $0–$1560), the direct out-of-pocket hospitalization cost at home (USD $35; range: $0–$120) and the direct out-of-pocket ambulatory costs at home (US$45; range: $0–$192). Respondents with dengue or malaria lost a median of USD $570 (Interquartile range [IQR] 240–1140) and USD $240 (IQR 0–600), respectively, due to their illness, whilst those with chikungunya and Zika virus lost a median of USD $2400 (IQR 1200–3600) and USD $1500 (IQR 510–2625), respectively. Conclusion: Travellers often incur significant costs due to travel-acquired diseases. Further research into the economic impact of these diseases on travellers should be conducted.

Predicting the dengue cluster outbreak dynamics in Yogyakarta, Indonesia: a modelling study

Ramadona, A. L., Tozan, Y., Wallin, J., Lazuardi, L., Utarini, A., & Rocklöv, J. (n.d.).

Publication year

2023

Journal title

The Lancet Regional Health - Southeast Asia

Volume

15
Abstract
Abstract
Background: Human mobility and climate conditions are recognised key drivers of dengue transmission, but their combined and individual role in the local spatiotemporal clustering of dengue cases is not well understood. This study investigated the effects of human mobility and weather conditions on dengue risk in an urban area in Yogyakarta, Indonesia. Methods: We established a Bayesian spatiotemporal model for neighbourhood outbreak prediction and evaluated the performances of two different approaches for constructing an adjacency matrix: one based on geographical proximity and the other based on human mobility patterns. We used population, weather conditions, and past dengue cases as predictors using a flexible distributed lag approach. The human mobility data were estimated based on proxies from social media. Unseen data from February 2017 to January 2020 were used to estimate the one-month ahead prediction accuracy of the model. Findings: When human mobility proxies were included in the spatial covariance structure, the model fit improved in terms of the log score (from 1.748 to 1.561) and the mean absolute error (from 0.676 to 0.522) based on the validation data. Additionally, showed only few observations outside the credible interval of predictions (1.48%) and weather conditions were not found to contribute additionally to the clustering of cases at this scale. Interpretation: The study shows that it is possible to make highly accurate predictions of the within-city cluster dynamics of dengue using mobility proxies from social media combined with disease surveillance data. These insights are important for proactive and timely outbreak management of dengue. Funding: Swedish Research Council Formas, Umeå Centre for Global Health Research, Swedish Council for Working Life and Social Research, Swedish research council VINNOVA and Alexander von Humboldt Foundation (Germany).

Private Payer-Negotiated Rates for FDA-Approved Head and Neck Cancer Immunotherapy and Chemotherapy Agents

Talwar, A., Kim, S., Yu, S., Samant, S., Tozan, Y., & Givi, B. (n.d.).

Publication year

2023

Journal title

Otolaryngology - Head and Neck Surgery

Volume

169

Issue

4

Page(s)

954-961
Abstract
Abstract
Objective: To quantify the price that private payers pay hospitals for head and neck squamous cell carcinoma (HNSCC) treatments and identify hospital-level factors associated with price variation. Study Design: Cross-sectional study. Setting: Price transparency files. Methods: Files from the top 50 hospitals in otolaryngology according to the US News and World Report were analyzed between December 2021 and June 2022. This study analyzed the following Food and Drug Administration-approved HNSCC therapies: pembrolizumab, nivolumab, cetuximab, cisplatin, carboplatin, and paclitaxel. Results: Twenty-four (48%) hospitals reported prices for at least 1 medication in our sample. Newer biologics were significantly more expensive than traditional chemotherapeutic agents. Given approved medication regimens, all biologics in our sample have similar annual costs. Price markups over acquisition costs ranged between 109% (pembrolizumab, nivolumab) and 530% for carboplatin. Across hospitals, prices varied the most for paclitaxel, the cheapest medication in our sample, and prices varied the least for pembrolizumab the most expensive medication in our sample. Hospital 340B status and geographic location in the northeast/west are associated with lower price markups. Conclusion: Price nondisclosure remains a significant problem among hospitals. Newer biological medications are more expensive when compared to traditional chemotherapeutic agents. Prices vary significantly across hospitals, with lower price markups observed in 340B hospitals as well as hospitals located in the geographic northeast and west. It remains to be seen if price transparency will lead to more uniform pricing or lower costs of treatments.

Self-Reported Adherence to Antiretroviral Therapy (ART) Among Women Engaged in Commercial Sex Work in Southern Uganda

Kiyingi, J., Nabunya, P., Kizito, S., Nabayinda, J., Nsubuga, E., Bahar, O. S., Jennings Mayo-Wilson, L., Namuwonge, F., Nattabi, J., Magorokosho, N., Tozan, Y., Witte, S. S., & Ssewamala, F. M. (n.d.).

Publication year

2023

Journal title

AIDS and Behavior

Volume

27

Issue

3

Page(s)

1004-1012
Abstract
Abstract
We examined the correlates of self-reported adherence to antiretroviral therapy (ART) among women engaged in commercial sex work (WESW) in Uganda. We used baseline data from a longitudinal study, which recruited 542 WESW in Southern Uganda. We used nested regression models to determine the individual and family, and economic level correlates of self-reported adherence. Study findings show that older age (OR = 1.07, 95% CI = 1.013, 1.139), secondary education (OR = 2.01, 95% CI = 1.306, 3.084), large household size (OR = 1.08, 95% CI = 1.020, 1.136), high family cohesion (OR = 1.06, 95% CI = 1.052, 1.065), and high financial self-efficacy (OR = 1.07, 95% CI = 1.006, 1.130) were associated with good self-reported adherence to ART. Married women (OR=-0.39, 95% CI = 0.197, 0.774), depression (OR = 0.85, 95% CI = 0.744, 0.969), alcohol use (OR = 0.72, 95% CI = 0.548, 0.954), ever been arrested (OR = 0.58, 95% CI = 0.341, 0.997), and high household assets ownership (OR = 0.48, 95% CI = 0.313, 0.724) were associated with poor self-reported adherence to ART. Findings suggest a need to adopt a multi-level approach to address gaps in ART adherence among WESW.

The effectiveness of malaria camps as part of the malaria control program in Odisha, India

Ompad, D. C., Padhan, T. K., Kessler, A., Tozan, Y., Jones, A. M., Van Eijk, A. M., Sullivan, S. A., Haque, M. A., Pradhan, M. M., Mohanty, S., Carlton, J. M., & Sahu, P. K. (n.d.).

Publication year

2023

Journal title

Scientific reports

Volume

13

Issue

1
Abstract
Abstract
Durgama Anchalare Malaria Nirakaran (DAMaN) is a multi-component malaria intervention for hard-to-reach villages in Odisha, India. The main component, malaria camps (MCs), consists of mass screening, treatment, education, and intensified vector control. We evaluated MC effectiveness using a quasi-experimental cluster-assigned stepped-wedge study with a pretest–posttest control group in 15 villages: six immediate (Arm A), six delayed (Arm B), and three previous interventions (Arm C). The primary outcome was PCR + Plasmodium infection prevalence. The time (i.e., baseline vs. follow-up 3) x study arm interaction term shows that there were statistically significant lower odds of PCR + Plasmodium infection in Arm A (AOR = 0.36, 95% CI = 0.17, 0.74) but not Arm C as compared to Arm B at the third follow-up. The cost per person ranged between US$3–8, the cost per tested US$4–9, and the cost per treated US$82–1,614, per camp round. These results suggest that the DAMaN intervention is a promising and financially feasible approach for malaria control.

"I expected little, although I learned a lot": perceived benefits of participating in HIV risk reduction sessions among women engaged in sex work in Uganda

Sensoy Bahar, O., Nabunya, P., Nabayinda, J., Witte, S. S., Kiyingi, J., Mayo-Wilson, L. J., Filippone, P., Yang, L. S., Nakigudde, J., Tozan, Y., & Ssewamala, F. M. (n.d.).

Publication year

2022

Journal title

BMC Women's Health

Volume

22

Issue

1
Abstract
Abstract
Background: The global HIV burden remains a public health concern. Women engaged in sex work (WESW) are at higher risk of acquiring HIV compared to the general adult population. Uganda reports high rates of HIV prevalence among WESW. While WESW in Uganda have long been the subject of surveillance studies, they have not been targeted by theory-informed HIV prevention intervention approaches. In this study, we explored the perceived benefits of an evidence-based HIV risk reduction intervention that was implemented as part of a combination intervention tested in a clinical trial in Uganda. Methods: As part of a larger randomized clinical trial, we conducted semi-structured in-depth interviews with 20 WESW selected using a stratified purposive sampling. All interviews were conducted in Luganda, language spoken in the study area, and audio-recorded. They were transcribed verbatim and translated to English. Thematic analysis was used to analyze the data. Results: WESW’s narratives focused on: (1) condom use; (2) alcohol/drug consumption; (3) PrEP use; (4) “handling” customers; and (5) "massaging” customers. WESW agreed that male condom was one of the important learning points for them and planned to continue using them while female condoms were received with mixed reactions. Many women appreciated receiving information about the risks of consuming alcohol and drugs, and discussed how they reduced/ eliminated their consumption. PrEP information was appreciated though identified by fewer WESW. Handling a client was discussed as a helpful strategy for safer sex through improved ability to convince customers to use condoms or avoiding sex. Massaging was also beneficial to avoid penetrative sex, but similar to female condom, massaging also yielded mixed perceptions. Conclusion: WESW found the intervention beneficial and described ways in which it improved their ability to engage in safer sex and stay healthy. The fact that WESW identified other strategies beyond condom use as helpful underlines the importance of adopting a comprehensive approach to behavioral interventions targeting HIV prevention even when combined with other interventions. Additionally, WESW’s narratives suggest that incorporating the tenets of social cognitive theory and harm reduction approaches in HIV prevention among this population can result in risk behavior change.

A Multilevel Integrated Intervention to Reduce the Impact of HIV Stigma on HIV Treatment Outcomes Among Adolescents Living With HIV in Uganda: Protocol for a Randomized Controlled Trial

Mutumba, M., Ssewamala, F., Namirembe, R., Bahar, O. S., Nabunya, P., Neilands, T., Tozan, Y., Namuwonge, F., Nattabi, J., Laker, P. A., Mukasa, B., & Mwebembezi, A. (n.d.).

Publication year

2022

Journal title

JMIR Research Protocols

Volume

11

Issue

10
Abstract
Abstract
Background: HIV stigma remains a formidable barrier to HIV treatment adherence among school-attending adolescents living with HIV, owing to high levels of HIV stigma within schools, rigid school structures and routines, lack of adherence support, and food insecurity. Thus, this protocol paper presents an evidence-informed multilevel intervention that will simultaneously address family- and school-related barriers to HIV treatment adherence and care engagement among adolescents living with HIV attending boarding schools in Uganda. Objective: The proposed intervention-Multilevel Suubi (MSuubi)-has the following objectives: examine the impact of M-Suubi on HIV viral suppression (primary outcome) and adherence to HIV treatment, including keeping appointments, pharmacy refills, pill counts, and retention in care; examine the effect of M-Suubi on HIV stigma (internalized, anticipated, and enacted), with secondary analyses to explore hypothesized mechanisms of change (eg, depression) and intervention mediation; assess the cost and cost-effectiveness of each intervention condition; and qualitatively examine participants' experiences with HIV stigma, HIV treatment adherence, and intervention and educators' attitudes toward adolescents living with HIV and experiences with group-based HIV stigma reduction for educators, and program or policy implementation after training. Methods: MSuubi is a 5-year multilevel mixed methods randomized controlled trial targeting adolescents living with HIV aged 10 to 17 years enrolled in a primary or secondary school with a boarding section. This longitudinal study will use a 3-arm cluster randomized design across 42 HIV clinics in southwestern Uganda. Participants will be randomized at the clinic level to 1 of the 3 study conditions (n=14 schools; n=280 students per study arm). These include the bolstered usual care (consisting of the literature on antiretroviral therapy adherence promotion and stigma reduction), multiple family groups for HIV stigma reduction plus family economic empowerment (MFG-HIVSR plus FEE), and Group-based HIV stigma reduction for educators (GED-HIVSR). Adolescents randomized to the GED-HIVSR treatment arm will also receive the MFG-HIVSR plus FEE treatment. MSuubi will be provided for 20 months, with assessments at baseline and 12, 24, and 36 months. Results: This study was funded in September 2021. Participant screening and recruitment began in April 2022, with 158 dyads enrolled as of May 2022. Dissemination of the main study findings is anticipated in 2025. Conclusions: MSuubi will assess the effects of a combined intervention (family-based economic empowerment, financial literacy education, and school-based HIV stigma) on HIV stigma among adolescents living with HIV in Uganda. The results will expand our understanding of effective intervention strategies for reducing stigma among HIV-infected and noninfected populations in Uganda and improving HIV treatment outcomes among adolescents living with HIV in sub-Saharan Africa.

Adapting a tobacco cessation treatment intervention and implementation strategies to enhance implementation effectiveness and clinical outcomes in the context of HIV care in Vietnam: a case study

Shelley, D., Alvarez, G. G., Nguyen, T., Nguyen, N., Goldsamt, L., Cleland, C., Tozan, Y., Shuter, J., & Armstrong-Hough, M. (n.d.).

Publication year

2022

Journal title

Implementation Science Communications

Volume

3

Issue

1
Abstract
Abstract
Background: Smoking rates remain high in Vietnam, particularly among people living with HIV/AIDS (PLWH), but tobacco cessation services are not available in outpatient HIV clinics (OPCs). The research team is conducting a type II hybrid randomized controlled trial (RCT) comparing the cost-effectiveness of three tobacco cessation interventions among PLWH receiving care in HIV clinics in Vietnam. The study is simultaneously evaluating the implementation processes and outcomes of strategies aimed at increasing the implementation of tobacco dependence treatment (TDT) in the context of HIV care. This paper describes the systematic, theory-driven process of adapting intervention components and implementation strategies with demonstrated effectiveness in high-income countries, and more recently in Vietnam, to a new population (i.e., PLWH) and new clinical setting, prior to launching the trial. Methods: Data collection and analyses were guided by two implementation science frameworks and the socio-ecological model. Qualitative interviews were conducted with 13 health care providers and 24 patients in three OPCs. Workflow analyses were conducted in each OPC. Qualitative data were analyzed using rapid qualitative analysis procedures. Based on findings, components of the intervention and implementation strategies were adapted, followed by a 3-month pilot study in one OPC with 16 patients randomized to one of two intervention arms. Results: The primary adaptations included modifying the TDT intervention counseling content to address barriers to quitting among PLWH and Vietnamese sociocultural norms that support smoking cessation. Implementation strategies (i.e., training and system changes) were adapted to respond to provider- and clinic-level determinants of implementation effectiveness (e.g., knowledge gaps, OPC resource constraints, staffing structure, compatibility). Conclusions: Adaptations were facilitated through a mixed method, stakeholder (patient and health care provider, district health leader)-engaged evaluation of context-specific influences on intervention and implementation effectiveness. This data-driven approach to refining and adapting components aimed to optimize intervention effectiveness and implementation in the context of HIV care. Balancing pragmatism with rigor through the use of rapid analysis procedures and multiple methods increased the feasibility of the adaptation process. Trial registration: ClinicalTrials.gov NCT05162911 . Registered on December 16, 2021.

Advancing scalability and impacts of a teacher training program for promoting child mental health in Ugandan primary schools: protocol for a hybrid-type II effectiveness-implementation cluster randomized trial

Huang, K. Y., Nakigudde, J., Kisakye, E. N., Sentongo, H., Dennis-Tiwary, T. A., Tozan, Y., Park, H., & Brotman, L. M. (n.d.).

Publication year

2022

Journal title

International Journal of Mental Health Systems

Volume

16

Issue

1
Abstract
Abstract
Background: Children in low-and-middle-income countries (LMICs) are facing tremendous mental health challenges. Numerous evidence-based interventions (EBIs) have been adapted to LMICs and shown effectiveness in addressing the needs, but most EBIs have not been adopted widely using scalable and sustainable implementation models that leverage and strengthen existing structures. There is a need to apply implementation science methodology to study strategies to effectively scale-up EBIs and sustain the practices in LMICs. Through a cross-sector collaboration, we are carrying out a second-generation investigation of implementation and effectiveness of a school-based mental health EBI, ParentCorps Professional Development (PD), to scale-up and sustain the EBI in Uganda to promote early childhood students’ mental health. Our previous studies in Uganda supported that culturally adapted PD resulted in short-term benefits for classrooms, children, and families. However, our previous implementation of PD was relied on mental health professionals (MHPs) to provide PD to teachers. Because of the shortage of MHPs in Uganda, a new scalable implementation model is needed to provide PD at scale. Objectives: This study tests a new scalable and sustainable PD implementation model and simultaneously studies the effectiveness. This paper describes use of collaboration, task-shifting, and Train-the-Trainer strategies for scaling-up PD, and protocol for studying the effectiveness-implementation of ParentCorps-PD for teachers in urban and rural Ugandan schools. We will examine whether the new scale-up implementation approach will yield anticipated impacts and investigate the underlying effectiveness-implementation mechanisms that contribute to success. In addition, considering the effects of PD on teachers and students will influence by teacher wellness. This study also examines the added value (i.e. impact and costs) of a brief wellness intervention for teachers and students. Methods: Using a hybrid-type II effectiveness-implementation cluster randomized controlled trial (cRCT), we will randomize 36 schools (18 urban and 18 rural) with 540 teachers and nearly 2000 families to one of three conditions: PD + Teacher-Wellness (PDT), PD alone (PD), and Control. Primary effectiveness outcomes are teachers’ use of mental health promoting strategies, teacher stress management, and child mental health. The implementation fidelity/quality for the scale-up model will be monitored. Mixed methods will be employed to examine underlying mechanisms of implementation and impact as well as cost-effectiveness. Discussion: This research will generate important knowledge regarding the value of an EBI in urban and rural communities in a LMIC, and efforts toward supporting teachers to prevent and manage early signs of children’s mental health issues as a potentially cost-effective strategy to promote child population mental health in low resource settings. Trial Registration: This trial was registered with ClinicalTrials.gov (registration number: NCT04383327; https://clinicaltrials.gov/ct2/show/NCT04383327) on May13, 2020.

Assessing the associations between Aedes larval indices and dengue risk in Kalutara district, Sri Lanka: a hierarchical time series analysis from 2010 to 2019

Liyanage, P., Tozan, Y., Tissera, H. A., Overgaard, H. J., & Rocklöv, J. (n.d.).

Publication year

2022

Journal title

Parasites and Vectors

Volume

15

Issue

1
Abstract
Abstract
Background: Dengue is a major public health problem in Sri Lanka. Aedes vector surveillance and monitoring of larval indices are routine, long-established public health practices in the country. However, the association between Aedes larval indices and dengue incidence is poorly understood. It is crucial to evaluate lagged effects and threshold values of Aedes larval indices to set pragmatic targets for sustainable vector control interventions. Methods: Monthly Aedes larval indices and dengue cases in all 10 Medical Officer of Health (MOH) divisions in Kalutara district were obtained from 2010 to 2019. Using a novel statistical approach, a distributed lag non-linear model and a two-staged hierarchical meta-analysis, we estimated the overall non-linear and delayed effects of the Premise Index (PI), Breteau Index (BI) and Container Index (CI) on dengue incidence in Kalutara district. A set of MOH division-specific variables were evaluated within the same meta-analytical framework to determine their moderator effects on dengue risk. Using generalized additive models, we assessed the utility of Aedes larval indices in predicting dengue incidence. Results: We found that all three larval indices were associated with dengue risk at a lag of 1 to 2 months. The relationship between PI and dengue was homogeneous across MOH divisions, whereas that with BI and CI was heterogeneous. The threshold values of BI, PI and CI associated with dengue risk were 2, 15 and 45, respectively. All three indices showed a low to moderate accuracy in predicting dengue risk in Kalutara district. Conclusions: This study showed the potential of vector surveillance information in Kalutara district in developing a threshold-based, location-specific early warning system with a lead time of 2 months. The estimated thresholds are nonetheless time-bound and may not be universally applicable. Whenever longitudinal vector surveillance data areavailable, the methodological framework we propose here can be used to estimate location-specific Aedes larval index thresholds in any other dengue-endemic setting. Graphical Abstract: [Figure not available: see fulltext.]

Costing of a Multiple Family Group Strengthening Intervention (SMART Africa) to Improve Child and Adolescent Behavioral Health in Uganda

Tozan, Y., Capasso, A., Namatovu, P., Kiyingi, J., Damulira, C., Nabayinda, J., Bahar, O. S., McKay, M. M., Hoagwood, K., & Ssewamala, F. M. (n.d.).

Publication year

2022

Journal title

The American journal of tropical medicine and hygiene

Volume

106

Issue

4

Page(s)

1078-1085
Abstract
Abstract
Reliable cost estimates are key to assessing the feasibility, affordability, and cost-effectiveness of interventions. We estimated the economic costs of a multiple family group (MFG) intervention-child and adolescent mental health evidence-based practices (CAMH-EBP) implemented under the SMART Africa study, seeking to improve family functioning and reduce child and adolescent behavior problems-delivered through task-shifting by community health workers (CHWs) or parent peers (PPs) in school settings in Uganda. This prospective microcosting analysis was conducted from a provider perspective as part of a three-armed randomized controlled trial of the MFG intervention involving 2,391 participants aged 8-13 years and their caregivers in 26 primary schools. Activity-specific costs were estimated and summed, and divided by actual participant numbers in each study arm to conservatively calculate total per-child costs by arm. Total per-child costs of the MFG-PP and MFG-CHW arms were estimated at US$346 and US$328, respectively. The higher per-child cost of the MFG-PP arm was driven by lower than anticipated attendance by participants recruited to this arm. Personnel costs were the key cost driver, accounting for approximately 70% of total costs because of intensive supervision and support provided to MFG facilitators and intervention quality assurance efforts. This is the first study estimating the economic costs of an evidence-based MFG intervention provided through task-shifting strategies in a low-resource setting. Compared with the costs of other family-based interventions ranging between US$500 and US$900 in similar settings, the MFG intervention had a lower per-participant cost; however, few comparisons are available in the literature. More costing studies on CAMH-EBPs in low-resource settings are needed.

Effect of El Niño–Southern Oscillation and local weather on Aedes dvector activity from 2010 to 2018 in Kalutara district, Sri Lanka: a two-stage hierarchical analysis

Liyanage, P., Tozan, Y., Overgaard, H. J., Aravinda Tissera, H., & Rocklöv, J. (n.d.).

Publication year

2022

Journal title

The Lancet Planetary Health

Volume

6

Issue

7

Page(s)

e577-e585
Abstract
Abstract
Background: Dengue, transmitted by Aedes mosquitoes, is a major public health problem in Sri Lanka. Weather affects the abundance, feeding patterns, and longevity of Aedes vectors and hence the risk of dengue transmission. We aimed to quantify the effect of weather variability on dengue vector indices in ten Medical Officer of Health (MOH) divisions in Kalutara, Sri Lanka. Methods: Monthly weather variables (rainfall, temperature, and Oceanic Niño Index [ONI]) and Aedes larval indices in each division in Kalutara were obtained from 2010 to 2018. Using a distributed lag non-linear model and a two-stage hierarchical analysis, we estimated and compared division-level and overall relationships between weather and premise index, Breteau index, and container index. Findings: From Jan 1, 2010, to Dec 31, 2018, three El Niño events (2010, 2015–16, and 2018) occurred. Increasing monthly cumulative rainfall higher than 200 mm at a lag of 0 months, mean temperatures higher than 31·5°C at a lag of 1–2 months, and El Niño conditions (ie, ONI >0·5) at a lag of 6 months were associated with an increased relative risk of premise index and Breteau index. Container index was found to be less sensitive to temperature and ONI, and rainfall. The associations of rainfall and temperature were rather homogeneous across divisions. Interpretation: Both temperature and ONI have the potential to serve as predictors of vector activity at a lead time of 1–6 months, while the amount of rainfall could indicate the magnitude of vector prevalence in the same month. This information, along with knowledge of the distribution of breeding sites, is useful for spatial risk prediction and implementation of effective Aedes control interventions. Funding: None.

Employment conditions as barriers to the adoption of COVID-19 mitigation measures: how the COVID-19 pandemic may be deepening health disparities among low-income earners and essential workers in the United States

Capasso, A., Kim, S., Ali, S. H., Jones, A. M., DiClemente, R. J., & Tozan, Y. (n.d.).

Publication year

2022

Journal title

BMC public health

Volume

22

Issue

1
Abstract
Abstract
Background: The COVID-19 pandemic has disproportionately impacted economically-disadvantaged populations in the United States (US). Precarious employment conditions may contribute to these disparities by impeding workers in such conditions from adopting COVID-19 mitigation measures to reduce infection risk. This study investigated the relationship between employment and economic conditions and the adoption of COVID-19 protective behaviors among US workers during the initial phase of the COVID-19 pandemic. Methods: Employing a social media advertisement campaign, an online, self-administered survey was used to collect data from 2,845 working adults in April 2020. Hierarchical generalized linear models were performed to assess the differences in engagement with recommended protective behaviors based on employment and economic conditions, while controlling for knowledge and perceived threat of COVID-19, as would be predicted by the Health Belief Model (HBM). Results: Essential workers had more precarious employment and economic conditions than non-essential workers: 67% had variable income; 30% did not have paid sick leave; 42% had lost income due to COVID-19, and 15% were food insecure. The adoption of protective behaviors was high in the sample: 77% of participants avoided leaving home, and 93% increased hand hygiene. Consistent with the HBM, COVID-19 knowledge scores and perceived threat were positively associated with engaging in all protective behaviors. However, after controlling for these, essential workers were 60% and 70% less likely than non-essential workers, who by the nature of their jobs cannot stay at home, to stay at home and increase hand hygiene, respectively. Similarly, participants who could not afford to quarantine were 50% less likely to avoid leaving home (AOR: 0.5; 95% CI: 0.4, 0.6) than those who could, whereas there were no significant differences concerning hand hygiene. Conclusions: Our findings are consistent with the accumulating evidence that the employment conditions of essential workers and other low-income earners are precarious, that they have experienced disproportionately higher rates of income loss during the initial phase of the COVID-19 pandemic and face significant barriers to adopting protective measures. Our findings underscore the importance and need of policy responses focusing on expanding social protection and benefits to prevent the further deepening of existing health disparities in the US.

Contact

tozan@nyu.edu 708 Broadway New York, NY, 10003