Introduction Adverse drug reactions are a major global public health concern and an important cause of hospitalization, discontinuation of the drug, morbidity and mortality. Even though the prevalence in Ethiopia was declining at a moderate rate, still, far too many people are suffering and dying unnecessarily due to adverse drug reactions. Objective The aim of this study was to determine the incidence of adverse drug reaction and its predictors among adult patients on antiretroviral therapy. Methods A retrospective follow-up study was conducted at Nigist Elleni Mohamed Memorial Comprehensive Specialized Hospital, Southern Ethiopia. Data were extracted from patients’ medical records. The Weibull model with gamma frailty distribution was fitted. Statistical significance was employed at a 5% level of significance and adjusted hazard ratio with 95% confidence interval was used. Results Out of the total 376 participants followed for 1988 person years of observations, 96 developed adverse reaction with the incidence rate of 4.820/100 per (95%CI: 4.102–5.317). The univariate frailty was statistically significant (theta=0.306, 95%CI: 0.102–0.521). Baseline CD4 count (AHR: 0.997, 95%CI: 0996–0.998), fair adherence (AHR: 2.358, 95%CI: 1.133–4.904), poor adherence (AHR: 3.069, 95%CI: 1.730–5.445), HIV/TB coinfection (AHR: 2.069, 95%CI: 1.115–3.843), WHO stage II (3.128, 95%CI: 1.414–6.916), WHO stage III (AHR: 2.709, 95%CI: 1.048–7.025) and WHO stage IV (1.516, 10.352) were associated with the incidence adverse reaction. Conclusion Most of the ADR cases occurred within two years after initiation of ART. Advanced clinical stage, TB coinfection, CD4 count, and poor adherence were predictors of ADRs. Continuous counseling for clients in advanced clinical stage and patients with TB coinfection need to get close follow-up to prevent the associated ADRs by the concerned parties.

Background:In Ethiopia, second-line anti-retroviral therapy (ART) for HIV/AIDS patients was started some years ago; however, few studies have reported the unfavorable outcomes of second-line ART. Therefore, this study aimed to assess the incidence and predictors of unfavorable outcomes and their association with change in viral load among adult HIV/AIDS patients on second-line treatment at selected public hospitals in Addis Ababa, Ethiopia. Methods: A retrospective follow-up study was conducted at selected public hospitals in Addis Ababa, Ethiopia, on 421 HIV/AIDS patients on second-line ART from 2016 to 2021. Cox proportional hazard models with a linear mixed effect model were jointly modeled using the JM package of R software with time-dependent lagged parameterizations, and a 95% confidence interval was used to select significant variables. Results: Overall, 89 HIV/AIDS patients developed unfavorable outcomes. The incidence density was 7.48/100 person-years (95% CI: