Background: Since the time of NACO Antiretroviral (ART) roll-out, generic ART has been the mainstay of therapy. There are many studies documenting the efficacy of generic ART but with the passage of time, failure of therapy is on the rise. As institution of second line ART has significant financial implications both for a program and for an individual it is imperative that we determine factors which contribute towards treatment failure in a cohort of patients on generic antiretroviral therapy.
Methodology: This was a nested matched case-control study assessing the predictors for treatment failure in our cohort who had been on Anti-retroviral therapy for at least a year. We identified 42 patients (Cases) with documented treatment failure out of our cohort of 823 patients and 42 sex, age and duration of therapy-matched controls. Using a structured proforma, we collected information from the out-patient and in-patient charts of the Infectious Diseases clinic Cohort in CMC, Vellore. A set of predetermined variables were studied as potential risk factors for treatment failure on ART.
Results: Univariate analysis showed significant association with 1) Self-reported nonadherence<95% [OR 12.81 (95%CI 1.54-281.45)]. 2) Treatment interruptions in adherent cases (OR 9.56 (95% CI 1.11-213.35)]. 3) Past inappropriate therapies [OR 9.65 (95% CI 1.12-215.94)]. 4) Diarrhoea [OR 16.40 (95% CI 2.02-3.55.960]. 5) GI opportunistic infections (OR 11.06 (95% CI 1.31 -244.27)] and 6) Drug Toxicity [OR 3.69 (95% CI 1.15-12.35).In multiple logistic regression analysis, we found independent risk factors of treatment failure to be: Self-reported non-adherence (<95%) with OR 15.46(95%CI 1.55 - 154.08), drug toxicity - OR 4.13(95%CI 1.095 - 15.534) and history of diarrhoea - OR 23.446(95%CI 2.572 - 213.70).
Conclusion: This study reveals that besides adherence to therapy, presence of diarrhoea and occurrence of drug toxicity are significant risk factors associated with failure of anti-retroviral therapy. There is a need for further prospective studies to assess their role in development of treatment failure on ART and thus help development of targeted interventions.