The effect of intake procedures on performance in methadone maintenance.

The effect of assessment and intake procedures on the outcome of methadone maintenance treatment was investigated in a natural experiment in which a single methadone clinic admitted 89 patients by a rapid intake procedure, and 74 patients who had been on a waiting list and underwent formal assessment interviews. Outcome measures were frequency of illicit drug use as detected by urine tests, and risk of dropping out or being expelled from treatment. Subjects admitted after prolonged, formal assessment were more likely to be expelled, and were more than twice as likely to leave during the first 400 days of maintenance treatment (95% Cl relative risk 1.1 to 5.2). The odds of formally assessed subjects using heroin in the first 6 months of treatment were twice those of the rapid intake group (95% Cl odds ratio 1.5 to 2.2). The formal assessment process deterred half the initial applicants, yet seems to have either selected individuals with a worse prognosis or to have had a negative effect on in-treatment performance.