Estimating the Prevalence of over- and Under-Reporting in HIV Testing, Status and Treatment in Rural Northeast South Africa: A Comparison of a Survey and Clinic Records

We assess the accuracy of self-reported testing, HIV status, and treatment responses compared to clinical records in Ehlanzeni District, South Africa. We linked a 2018 population-based survey of adults 18-49 years old with clinical data at local primary healthcare facilities from 2014 to 2018. We calculated self-reported testing, HIV status, and treatment, and triangulated findings with clinic record data. We adjusted testing estimates for known gaps in HIV test documentation. Of 2089 survey participants, 1657 used a study facility and were eligible for analysis. Half of men and 84% of women reported an HIV test in the past year. One third of reported tests could be confirmed in clinic data within 1 year and an additional 13% within 2 years; these fractions increased to 57% and 22% respectively limiting to participants with a verified clinic file. After accounting for gaps in clinic documentation, we found that prevalence of recent HIV testing was closer to 15% among men and 51% in women. Estimated prevalence of known HIV was 16.2% based on self-report vs. 27.6% with clinic documentation. Relative to clinical records among confirmed clinic users, self report of HIV testing and of current treatment were highly sensitive but non-specific (sensitivity 95.5% and 98.8%, specificity 24.2% and 16.1% respectively), while self report of HIV status was highly specific but not sensitive (sensitivity 53.0%, specificity 99.3%). While clinical records are imperfect, survey-based measures should be interpreted with caution in this rural South African setting.
HIV testing; South Africa; self-reported measures; survey research.