This was a sub-analysis of data from the EFFINAC study [6] that retrieved medical records across six public Kampala Capital City Authority (KCCA) health facilities described previously [7, 8]. The EFFINAC study evaluated the impact of IAC on VL suppression and mortality among PLHIV on first-line ART, with the intervention group as those who had received ≥ 3 consecutive IAC sessions provided 1 month apart (n = 114) and comparison as those who received psychosocial support (n = 3085). The study sites provide standardized HIV/ART care following the national treatment guidelines. The first VL testing is done after 6 months of ART initiation and subsequent tests are done annually if one is virally suppressed. If one is not virally suppressed, IAC is provided according to guidelines. The parent study received ethical approvals from the Infectious Diseases Institute Research Ethics Committee (#IDI-REC-2022-18) and the Uganda National Council for Science and Technology (#HS25553ES), and administrative clearance from the Directorate of Public Health and Environment, KCCA (#DPHE/KCCA/1301). The study considered participants initiated on first-line ART between November 1, 2020, and November 30, 2021, with the data retrieval period as November 1, 2022, to January 5, 2023. For this nested case-control study, the IDI-REC and UNCST provided a waiver of informed consent since the study was embedded within the parent study [6]. PLHIV aged ≥ 15 years with repeat unsuppressed VL (VL ≥ 1000 copies/ml) after ≥ 3 IAC sessions were considered as cases (n = 16) and a 2:1 random sample of those with repeat suppressed VL (VL < 1000 copies/ml) were selected as controls (n = 32).

We excluded PLHIV that transferred to other health facilities and those that died before a repeat VL testing. We summarized numerical data using mean and standard deviation (when normally distributed) and categorical data using frequencies and percentages. Bivariate analysis used Fisher’s exact test to assess differences in proportions between cases and controls. Mean differences in numerical data between cases and controls were assessed using Student’s t-test for normally distributed data, otherwise, the Wilcoxon-rank sum test was used. Socially and clinically relevant variables from the literature and those with p < 0.1 at the bivariate analysis were included in the multivariable logistic regression analysis to determine whether the number of IAC sessions is associated with suppressed VL. We reported odds ratio (aOR) and 95% confidence interval (CI).