RESUMEN
Background: Cocaine users tend to have a higher frequency of risk behaviors. Aim: To compare risk behaviors of out of treatment Cocaine Base Paste (CBP) and Cocaine Hydrochloride (CH) users, by means of Privileged Access Interviewing in a one year prospective study. Material and Methods: Twenty eight interviewers were trained to recruit and administer a questionnaire on substance use patterns and related risk behaviors. Intentioned sampling was carried out in four municipalities of Santiago, Chile. Subjects who used CBP (group 1) or CH (group 2) at least once in the last month, with primary current use of CBP (group 1) or CH (group 2), and without treatment for substance abuse in the last six months were interviewed. Generalized Estimating Equations (GEE) were employed to compare risk behaviors during follow up. Results: Four hundred and two of 467 subjects (86.1%) were followed up for one year. CBP users (n = 204) reported greater frequency of self inflicted injuries (Odds Ratio (OR): 1.97 [95% confidence intervals (CI): 1.073.66]) and suicide attempts (OR: 2.68 [95% CI: 1.196.01]) than CH users. Conclusions: CBP users had a greater frequency of self inflicted injuries and suicide attempts, both life threatening risk behaviors, than CH users. This profile shows the high vulnerability of CBP users and should encourage further research and design of outreach interventions, particularly focused on this group.