Gopalappa, Chaitra, John Stover, and Carel Pretorius. 2013. HIV Prevalence Patterns by Age and Sex: Exploring Differences Among 19 Countries. DHS Analytical Studies No. 40. Calverton, Maryland, USA: ICF International.
Parameters of interest in estimating model-based projections of HIV prevalence include HIV incidence patterns by age, which we express as HIV incidence in an age group relative to HIV incidence in age 25-29. Questions of interest include, are these age patterns similar or significantly different across countries with generalized HIV epidemics, and if different, are there any age-based behavioral variables that explain those differences? As incidence cannot be measured directly, this study seeks to address these questions using HIV prevalence patterns from 28 DHS datasets covering 19 countries with generalized HIV epidemic.This analysis finds that an average pattern of HIV prevalence by age generally matches the country-specific patterns. In some cases, however, mostly in older age groups and in a few cases in the younger age groups, the HIV prevalence pattern differs significantly from the average pattern. The analysis identifies years since the introduction of antiretroviral therapy (ART) and maturity of the HIV epidemic as significantly correlated with HIV prevalence pattern for women and men in older age groups, and the proportion sexually active or proportion with condom use as factors among young women that are significantly correlated with HIV prevalence pattern. The significance of ART as a factor in particular points to the need for continuing to identify changes in HIV prevalence patterns over time, especially as access to ART may not be similar across all age groups.