Incidence and factors associated with treatment failure among HIV infected adolescent and adult patients on second-line antiretroviral therapy in public hospitals of Northern Ethiopia: Multicenter retrospective study

This study aimed to determine the incidence and factors associated with treatment failure among HIV infected adolescent and adult patients on second-line antiretroviral therapy (ART) in public hospitals of Northern Ethiopia. A retrospective study was conducted from September 1, 2007 to July 30, 2017 on 227 patients. The data were extracted using a retrieval checklist from the patient's charts. The incidence rate of treatment failure was calculated using Kaplan-Meier methods and Cox proportional hazard model was used to assess factors associated with treatment failure. The study subjects were followed for a total observation of 788.58 person-years with a median follow-up period of 35 (IQR: 17-60) months after switching to second-line ART. About 57 (25.11%) patients developed treatment failure, out of which, 32 (56.14%) occurred during the first two years. The overall incidence of second-line treatment failure was 72.3 per 1000 person years (95%CI: 55.75-93.71) of observation. The Kaplan-Meier estimates of cumulative treatment failure after 1, 2, and around 10 years of follow-up were 12.31% (95%CI: 8.60-17.45%), 14.99% (95%CI: 10.82%-20.57%), and 48.67% (95%CI: 32.45-67.81%) respectively. Age >45 years AHR = 3.33, 95%CI = 1.33-8.31), WHO stage IV (AHR = 3.63, 95%CI = 1.72-7.67), CD4 count