Comparing Estimates of Multiple and Concurrent Partnerships Across Population Based Surveys: Implications for Combination HIV Prevention

Abstract

We compare estimates of multiple and concurrent sexual partnerships from Demographic and Health Surveys (DHS) with comparable Population Services International (PSI) surveys in four African countries (Kenya, Lesotho, Uganda, Zambia). DHS data produce significantly lower estimates of all indicators for both sexes in all countries. PSI estimates of multiple partnerships are 1.7 times higher [1.4 for men (M), 3.0 for women (W)], cumulative prevalence of concurrency is 2.4 times higher (2.2 M, 2.7 W), the point prevalence of concurrency is 3.5 times higher (3.5 M, 3.3 W), and the fraction of multi-partnered persons who report concurrency last year is 1.4 times higher (1.6 M, 0.9 W). These findings provide strong empirical evidence that DHS surveys systematically underestimate levels of multiple and concurrent partnerships. The underestimates will contaminate both empirical analyses of the link between sexual behavior and HIV infection, and theoretical models for combination prevention that use these data for inputs.

Fig. 1

Prevalence of multiple partnerships in the last 12 months by country and age in the PSI surveys versus the DHS surveys. First panel compares the estimated prevalence (population percentage) by country for each sex. Second panel compares the prevalence by age for each sex, with the data pooled for all four countries. Cases are weighted to produce the DHS weighted sample composition by age, sex and marital status by country for both surveys

Fig. 2

Ratios of estimated concurrency prevalence, PSI to: DHS—“Original” uses data weighted by the original sample weights for each survey, “Composition Adjusted” uses data weighted to have the same age-sex-marital status composition as the DHS samples, and “2+ partners” is restricted to persons reporting multiple partners in the last year, again using DHS sample weights. Values greater than 1 (dark black line) indicate PSI estimates are higher by the factor shown on the y-axis. The DHS underestimates of the point prevalence of concurrency are particularly severe, and the variations by sex and country are statistically significant