Advanced HIV disease and treatment-related adverse drug reactions among people living with HIV receiving antiretroviral therapy in Tanzania: a multicenter cross-sectional study

Background: Advanced HIV disease (AHD) remains a major contributor to HIV-related morbidity and mortality despite widespread antiretroviral therapy (ART) access in sub-Saharan Africa. Although treatment-related adverse drug reactions (ADRs) may compromise treatment outcomes, evidence on the relationship between AHD and ADR occurrence remains limited. This study aimed to determine the prevalence and identify factors associated with AHD, characterize treatment-related ADR and assess the association between AHD and ADR occurrence among people living with HIV receiving ART in Dar es Salaam, Tanzania. Methods: We conducted a multicenter cross-sectional study among 1,513 people living with HIV receiving ART at selected HIV care and treatment clinics in Dar es Salaam, TanzaniaFor this adolescent/adult cohort, AHD was operationally defined as WHO clinical stage III/IV disease and/or baseline CD4 count <200 cells/mm3. Treatment-related ADRs were defined as participant-reported and/or clinically documented ART-related adverse events identified during routine HIV care, including both current and retrospectively reported events. Modified Poisson regression with robust standard errors was used to estimate crude and adjusted risk ratios (RRs) with 95% confidence intervals (CIs). Results: Among 1,508 participants with sufficient information for classification, 961 (63.7%) had AHD. Factors independently associated with AHD included age [&ge;]50 years (aRR 1.10, 95% CI 1.01-1.20), underweight nutritional status (aRR 1.17, 95% CI 1.00-1.35), and concomitant medication use (aRR 1.19, 95% CI 1.03-1.37), while DTG-based ART was associated with lower AHD prevalence (aRR 0.78, 95% CI 0.68-0.90). Overall, 569 participants (38.0%) reported at least one ADR. Composite AHD was not independently associated with ADR occurrence (aRR 0.95, 95% CI 0.82-1.11), but baseline CD4 <200 cells/mm3 was associated with increased ADR risk (aRR 1.20, 95% CI 1.02-1.41). Comorbidity (aRR 1.66, 95% CI 1.42-1.93) was the strongest correlate of ADR occurrence. Conclusion: AHD remains highly prevalent among people living with HIV receiving ART in Tanzania. While composite AHD was not independently associated with ADR occurrence, severe immunosuppression, comorbidity burden, and concomitant medication exposure were associated with increased ADR risk. These findings suggest that immunologic severity and broader clinical complexity may be more informative predictors of ART-related toxicity than composite syndromic AHD classification alone. Strengthened early diagnosis, differentiated advanced HIV care, integrated pharmacovigilance strategies, and routine medication risk assessment are needed.