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

BACKGROUND: 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. METHODS: 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. RESULT: 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 <100 cells/mm(3) (AHR = 3.79, 95%CI = 1.61–8.91), TB co-morbidity (AHR = 3.39 95%CI = 1.91–6.01) and poor adherence level (AHR = 3.63, 95% CI = 1.89–6.96) at the start of second line ART were significantly associated with second-line ART failure. CONCLUSION: Incidence of second-line ART treatment failure in the first 2 years of follow-up was high. The rate of second-line ART failure was higher in patients who started second-line ART with poor drug adherence, CD4 count <100 cells/mm(3), TB co-morbidity, age >45 years, and being in WHO stage IV. Therefore, intensive counseling and adherence support should be given along with strong TB screening. Moreover, the government of Ethiopia should consider endorsing third-line ART drugs after careful cost–benefit analysis.