Joint Modeling of Incidence of Unfavorable Outcomes and Change in Viral Load Over Time Among Adult HIV/AIDS Patients on Second-Line Anti-Retroviral Therapy, in Selected Public Hospitals of Addis Ababa, Ethiopia

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: 6.08, 9.2). Secondary and tertiary educational level (AHR=0.47, 95% CI: 0.25, 0.89, and AHR=0.27, 95% CI: 0.1, 0.72), CD4 count less than 100 cells/mm(3) (AHR=2.15, 95% CI: 1.21, 3.83), poor adherence (AHR=3.59, 95% CI: 1.73, 7.49), and TB comorbidity (AHR=2.23, 95% CI: 1.21, 4.14) at the start of second-line ART were significant predictors of incidence of unfavorable outcome. Time-dependent lagged value viral load was significantly associated with the risk of unfavorable outcome (AHR=1.28, 95% CI: 1.01, 1.63). CONCLUSION: In the study area, the incidence of an unfavorable outcome of second-line ART was high. Secondary and tertiary educational level, CD4 count less than 100 cells/mm(3), poor adherence, and TB comorbidity at the start of second-line ART were significant predictors of incidence of unfavorable outcomes. Thus, strengthening routine viral load measurement, increase patient adherence, intensive counseling, and strong TB screening are needed in the study setting.