Evolution of drug use in a cohort of treated crack cocaine users.

OBJECTIVE To analyze the evolution of drug use among treated crack cocaine users. METHODS A cohort originally comprising 131 crack addicts admitted to a detoxification unit in the city of São Paulo, Southeastern Brazil, between 1992 and 1994 were followed up on three occasions: 1995-96, 1998-99, and 2005-06. Variables investigated included demographical data, risky sexual behaviors, intake patterns for crack and other substances, incarceration, disappearance, and death. Statistical analysis was carried out using chi-square tests, multinomial logistic regression and Cox regression. RESULTS Among the patients evaluated, 43 were crack-free (12 months or longer), 22 were users, 13 were imprisoned, two were missing, and 27 were deceased. Three groups with distinct post-discharge drug use patterns were identified. Safe sexual behavior (condom use) was correlated with stable abstinence (p=0.001). Positive HIV test upon admission (p=0.046), use of snorted cocaine in the last year (p=0.001), and lifetime use of snorted cocaine (132 months or longer) (p=0.000) were associated with long term use of crack cocaine. History of intravenous cocaine use increased the probability of death at 12 years by 2.5 fold (p=0.031) (95%CI: 1.08; 5.79). CONCLUSIONS Recurrence and persistence of crack use in the years following discharge reflect new modalities of drug use. On the other hand, stable abstinence patterns provide evidence of the feasibility of recovery from crack addiction.