Title: High prevalence of self-reported sexually transmitted diseases among older adults in Tanzania: results from the list experiment
Authors: Kim HY, Rohr J, Leyna GH, Killewo J, Tomita A, Tanser F, BÃÂ¤rnighausen T.
Journal: Ann Epidemiol.,S1047-2797(23)00086-8. doi: 10.1016/j.annepidem.2023.05.001: (2023)
Background: Self-report of sensitive sexual behaviors is often inaccurate and subject to social desirability bias. List experiment is an alternative survey method to mitigate biases. The objective of this study was to estimate the rate of sexually transmitted infections (STIs) among older adults in urban Tanzania using the list experiment and to compare it with the estimate from direct questioning.
Methods: The study was nested within the Dar es Salaam Urban Cohort Study, the Health and Demographic Surveillance System (HDSS) in Ukonga, Tanzania. Men and women aged ?40 years were randomly assigned to receive a list of either four control items (i.e., control group), or four control items plus an additional item on having had a disease through sexual contracts in the past 12 months (i.e., treatment group). We calculated the mean difference in the total number of items to which respondents responded "yes" in the treatment vs. control groups, and compared it to the proportion measured in direct questioning. Multivariate linear and non-linear regression models were also fitted.
Results: A total of 2310 adults aged ?40 years was enrolled in the study: 32% were male, and 48% were aged 40-49 years. The estimated prevalence of having sexually transmitted infections (STIs) in the past 12 months was 17.8% (95% Confidence Interval [CI] 12.3-23.3) in the list experiment, almost 10 times higher compared to 1.8% (95%CI 1.3-2.4) when directly asked (p<0.001). The prevalence was higher in men (27.0%; 95%CI 17.0-37.0) than in women (12.9%; 95%CI 6.4-19.4). The prevalence remained high after adjusting for age, multiple lifetime partners, and other sociodemographic factors in multivariate linear regression (15.6%; 95%CI 7.3-23.9).
Conclusions: The study found a higher estimated prevalence of STIs among older adults in urban Tanzania using the list experiment than when directly asked. This highlights the need for screening of STIs including HIV to ensure effective prevention and treatment in older adults.
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Citation: Kim HY, Rohr J, Leyna GH, Killewo J, Tomita A, Tanser F, BÃ¤rnighausen T. High prevalence of self-reported sexually transmitted diseases among older adults in Tanzania: results from the list experiment Ann Epidemiol.,S1047-2797(23)00086-8. doi: 10.1016/j.annepidem.2023.05.001: (2023).