Patterns and Correlates of Sustained Heroin Abstinence: Findings From the 11-Year Follow-Up of the Australian Treatment Outcome Study.

Abstract

We report on patterns and correlates of sustained abstinence at the 11-year follow-up of the Australian Treatment Outcome Study cohort. This report is a longitudinal cohort analysis of patterns of recent and sustained abstinence. A total of 431 (70.1%) of the original 615 participants were interviewed, and 10.2% were deceased. The mean elapsed time since heroin initiation was 20.4 years (SD = 7.2). At the 11-year follow-up, heroin abstinence over the preceding month was reported by 75.2%. A period of at least 1 month's abstinence across the follow-up was reported by 97.7% and at least 1 year by 89.9%, whereas 52.2% reported an abstinence period of 5 or more consecutive years. Sustained abstinence across the entire follow-up period was reported by 5.6%. Independent correlates of 5 or more consecutive years of heroin abstinence were female gender (odds ratio [OR] = 1.73), not being currently enrolled in a drug treatment program (OR = 2.16), and fewer treatment episodes across the follow-up (OR = 0.90, 95% CI [0.85, 0.96]). The clinical profile of the cohort at the 11-year follow-up was encouraging, with the majority currently heroin abstinent, a proportion that has increased across time. Although only a small minority maintained abstinence over the entire period, half had sustained abstinence for at least 5 consecutive years. With the exception of gender, baseline characteristics made poor predictors of long-term abstinence. Treatment stability, however, appears crucial in maintaining abstinence.