Declining but increasingly concentrated HIV stigma in rural Uganda: population-based cohort study, 2014-2024.

Background: HIV-related stigma remains a primary barrier to the elimination of the HIV epidemic worldwide. No studies have examined long-term changes in the distribution of stigmatizing attitudes within populations. Methods: We conducted a whole-population, open cohort study of adults in 8 villages in rural southwestern Uganda, with 5 biennial surveys spanning 2014-2024 (N=1,776 at baseline; 869 participated in all waves). We measured individual negative attitudes toward people with HIV ("public stigma") and perceptions of negative attitudes among others ("perceived stigma") using parallel 15-item scales. We estimated mean stigma scores, computed inequality measures at each wave, and decomposed inequality by sociodemographic characteristics. Leveraging the cohort design, we estimated intraclass correlation coefficients and rank-order stability over time. Results: Both public and perceived stigma declined substantially from baseline to endline and became concentrated in an increasingly smaller subgroup of the population. Theil decomposition failed to identify any stratifying variables that explained more than 3% of this variation: nearly all the inequality in HIV stigma occurred within population subgroups rather than between them. In longitudinal analyses, public stigma showed trait-like properties (intraclass correlation coefficient=0.35; 95% CI, 0.31-0.38) and meaningful rank-order stability (baseline-to-endline r=0.41). Perceived stigma showed no rank-order stability, no appreciable between-person variance, and universal convergence to low levels regardless of baseline. Conclusions: Both public and perceived HIV stigma declined substantially in this rural Ugandan population, but remaining public stigma has become concentrated within a persistent minority. Sociodemographic profiling to target individuals who carry persistently negative attitudes toward people with HIV is unlikely to succeed.