Patterns of illicit drug use and retention in a methadone program: a longitudinal study

This study aimed to analyze illicit drug use of participants in a methadone treatment program in relation to methadone dose, counseling, and retention.

This was a longitudinal study of a cohort of 204 heroin-dependent subjects admitted for the first time to a methadone program in Stockholm. The patients were admitted between 1995 and mid-2000 and were followed until December 2000 or discharge. Up to June 11, 1998, individual psychosocial counseling was provided; after this date individual counseling was replaced with group counseling. Clinical data were collected from patient records and from a laboratory database. Rates of drug-positive urine analyses during different time periods were measured.

The mean observation time was 2.5 years for all patients. The one-year retention rate was 84 percent, and the two-year rate was 65 percent, with no major differences between the two counseling groups. Almost all patients relapsed to illicit drug use. Discharged patients had a significantly higher rate of positive urine samples (21 percent versus 9 percent) than patients who remained in treatment. Also, low methadone dose and younger age predicted discharge from treatment.

The frequent urine monitoring showed that illicit drug use was rather common, even in a program with structured psychosocial interventions, although it was lower than in other studies. This testing policy can be used for early identification of patients at risk for drop-out or discharge who should be offered complementary interventions.