Incidence of discontinuation of highly active antiretroviral combination therapy (HAART) and its determinants

Objective: To determine the incidence and determinants for discontinuation of initial highly active antiretroviral therapy (HAART). Design: In this retrospective follow-up study from hospital files and pharmacy dispensing data, a standard dataset was collected including patient characteristics, therapy characteristics, and HIV-monitoring parameters (e.g., CD4+ lymphocyte counts, viral load determinations). Kaplan-Meier estimates of the cumulative probability of discontinuation of initial HAART were calculated. Cox proportional hazard analysis was used to identify determinants for discontinuation of initial HAART. Patients: All patients starting HAART (n = 99) during June 1996 to February 1997 at our regional AIDS center. Main Outcome Measures: Incidence and determinants for discontinuation of HAART. Results: During the mean follow-up of 450 ± 10 days, 27 patients switched initial HAART, 3 patients stopped any antiretroviral therapy. Reasons for switching were increasing viral load (18x), insufficient decrease of viral load (3x), and adverse events (6x). Nonnaivete for antiretroviral therapy and a lower CD4+ lymphocyte count at start were identified as determinants for discontinuation of initial HAART. Conclusions: The overall incidence density for discontinuation of initial HAART was 25 per 100 patients/year. The main reason for switching was an increasing viral load. CD4+ lymphocyte counts at start and nonnaivete for antiretroviral therapy were identified as determinants for discontinuation.