Predictors of patient retention in a newly established methadone maintenance treatment programme.

AIMS

To identify predictors of patient retention in methadone maintenance.

DESIGN

Prospective study.

SETTING

Methadone maintenance treatment programme newly established in Geneva, Switzerland.

PARTICIPANTS

All patients who initiated treatment between February 1991 and January 1995.

MEASUREMENTS

Baseline patient characteristics, dose of methadone, year of enrollment and retention in treatment.

FINDINGS

Overall, 111 patients contributed 164.4 person-years of follow-up. The retention rate was 84% after 12 months. In multivariate analysis, the risk of dropping out was significantly higher for patients who had been using opioids for < or = 7 years (relative hazard (RH) 3.0, 95% confidence interval (CI) 1.2-7.4), and for patients who had no stable income at baseline (RH 3.3, 95% CI 1.2-9.1). Dropouts were less frequent at the highest doses of methadone (65-110 mg/day, RH 1.0) than at middle doses (45-60 mg/day, RH 2.0, 95% CI 0.7-5.5) but, quite unexpectedly, dropouts were least likely at the lowest doses (15-40 mg/day, RH 0.5, 95% CI 0.1-1.8). Dropouts were more likely among patients who enrolled in the first (RH 6.2, 95% CI 2.3-16.7) and second (RH 1.9, 95% CI 0.6-5.6) years of the programme, compared with subsequent years (RH 1.0).

CONCLUSIONS

Patients who have a long history of drug use and who have a stable income were more likely to stay in methadone maintenance treatment. Independent of patient characteristics, retention improved dramatically in the first years of programme functioning, suggesting that patient retention is a sensitive indicator of programme performance.