Context.-Clinical trials have established the efficacy of antiretroviral therapy with double-and triple-drug regimens for individuals infected with the human immunodeficiency virus (HIV), but the effectiveness of these regimens in the population of patients not enrolled in clinical trials is unknown.Objective.-To characterize survival following the initiation of antiretroviral therapy among HIV-infected individuals in the province of British Columbia.Design.-Prospective, population-based cohort study of patients with antiretroviral therapy available free of charge (median follow-up, 21 months).Setting.-Province of British Columbia, Canada.Patients.-All HIV-positive men and women 18 years of age or older in the province who were first prescribed any antiretroviral therapy between October 1992 and June 1996 and whose CD4 + cell counts were less than 0.350ϫ10 9 /L. Main Outcome Measures.-Rates of progression from initiation of antiretroviral therapy to death or a primary acquired immunodeficiency syndrome (AIDS) diagnosis for subjects who initially received zidovudine-, didanosine-, or zalcitabinebased therapy (ERA-I) and for those who initially received therapy regimens including lamivudine or stavudine (ERA-II).Results.-A total of 1178 patients (951 ERA-I, 227 ERA-II) were eligible. A total of 390 patients died (367 ERA-I, 23 ERA-II), yielding a crude mortality rate of 33.1%. ERA-I group subjects were almost twice as likely to die as ERA-II group subjects, with a mortality risk ratio of 1.86 (95% confidence interval [CI], 1.21-2.86; P=.005). After adjusting for Pneumocystis carinii and Mycobacterium avium prophylaxis use, AIDS diagnosis, CD4 + cell count, sex, and age, ERA-I participants were 1.93 times (95% CI, 1.25-2.97; P=.003) more likely to die than ERA-II participants. Among patients without AIDS when treatment was started, ERA-I participants were 2.50 times (95% CI, 1.59-3.93; PϽ.001) more likely to progress to AIDS or death than ERA-II participants.Conclusion.-The HIV-infected individuals who received initial therapy with regimens including stavudine or lamivudine had significantly lower mortality and longer AIDS-free survival than those who received initial therapy with regimens limited to zidovudine, didanosine, and zalcitabine.

Our data demonstrate uniformly low rates of disease progression to death and AIDS or death among patients starting antiretroviral therapy with CD4 cell counts of at least 200/microL. In our study, disease progression to death and AIDS or death was clustered among patients starting therapy with CD4 cell counts less than 200/microL.

Context.-In British Columbia, human immunodeficiency virus (HIV)-infected persons eligible for antiretroviral therapy may receive it free but the extent to which HIV-infected injection drug users access it is unknown. Objective.-To identify patient and physician characteristics associated with antiretroviral therapy utilization in HIV-infected injection drug users. Design.-Prospective cohort study with record linkage between survey data and data from a provincial HIV/AIDS (acquired immunodeficiency syndrome) drug treatment program. Setting.-British Columbia, where antiretroviral therapies are offered free to all persons with HIV infection with CD4 cell counts less than 0.50ϫ10 9 /L (500/µL) and/or HIV-1 RNA levels higher than 5000 copies/mL. Subjects.-A total of 177 HIV-infected injection drug users eligible for antiretroviral therapy, recruited through the prospective cohort study since May 1996. Main Outcome Measures.-Patient use of antiretroviral drugs through the provincial drug treatment program and physician experience treating HIV infection. Results.-After a median of 11 months after first eligibility, only 71 (40%) of 177 patients had received any antiretroviral drugs, primarily double combinations (47/ 71 [66%]). Both patient and physician characteristics were associated with use of antiretroviral drugs. After adjusting for CD4 cell count and HIV-1 RNA level at eligibility, odds of not receiving antiretrovirals were increased more than 2-fold for females (odds ratio [OR], 2.53; 95% confidence interval [CI], 1.08-5.93) and 3-fold for those not currently enrolled in drug or alcohol treatment programs (OR, 3.49; 95% CI, 1.45-8.40). Younger drug users were less likely to receive therapy (OR, 0.47/ 10-y increase; 95% CI, 0.28-0.80). Those with physicians having the least experience treating persons with HIV infection were more than 5 times less likely to receive therapy (OR, 5.55; 95% CI, 2.49-12.37). Conclusions.-Despite free antiretroviral therapy, many HIV-infected injection drug users are not receiving it. Public health efforts should target younger and female drug users, and physicians with less experience treating HIV infection.

Our study demonstrates that even after adjusting for other prognostic factors intermittent use of antiretroviral therapy was associated with increased mortality.

Injecting cocaine use was a strong, dose-dependent predictor of HIV seroconversion in this poly-drug using population. Injection cocaine users remain particularly vulnerable to HIV infection and treatment options for cocaine dependency remain woefully inadequate.