Uniform risk of clinical progression despite differences in utilization ofhighly active antiretroviral therapy: Swiss HIV Cohort Study

Objective: To compare the initiation of highly active antiretroviral therap y (HAART) in HIV-infected patients according to sex, route of HIV acquisiti on and education, and to assess the impact of differences in utilization on the probability of progression to AIDS. Design and setting: Swiss HIV Cohort Study, a national prospective multi-ce ntre study. Participants: A total of 3342 patients, including 1007 (30%) women. HIV was acquired through injection drug use in 1155 (35%) cases and through sex be tween men in 1172 (35%). Twenty-eight per cent (957) of participants had at tained only the minimum level of schooling. At baseline, the median CD4 cel l count was 269 x 10(6)/l cells, median HIV-1 RNA was 4.3 log(10) copies/ml and 2917 (87%) were free of AIDS. Methods: Kaplan-Meier life tables and Cox proportional hazards regression. Results: During 7007 person-years of follow-up 2285 (69%) patients started HAART and 318 (10%) developed a new AIDS event. In multivariable analysis c ontrolling for CD4 cell count, viral load and disease stage at baseline, th e probability of starting HAART was lower in injection drug users compared with men who have sex with men, hazard ratio 0.63 (95% confidence intervals 0.56-0.70) and in patients with minimum schooling compared with those with vocational training, hazard ratio 0.82 (0.75-0.91). The risk of progressio n to AIDS was similar among men and women, patients with a history of injec ting drug use, and patients with lower educational attainment in both univa riable and multivariable analysis. Conclusion: HIV-infected injecting drug users and those with lower levels o f educational attainment start HAART later than other patient groups. The d eferred initiation of therapy in these patients does not, however, appear t o translate into an increased risk of clinical disease progression. This ob servation has important implications for treatment policy and the design of future clinical trials. (C) 1999 Lippincott Williams & Wilkins.