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 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