Methadone dosage and retention: an examination of the 60 mg/day threshold.

A National Institutes of Health (NIH) expert panel has mentioned a daily methadone dose of at least 60 mg as a best practice in methadone maintenance. The focus of this research is to estimate the percentage of outpatient methadone clients receiving this level of methadone and examine the association between treatment retention and level of methadone dosage as recommended by the NIH expert panel. A sample of 428 methadone clients discharged from methadone treatment facilities from the Alcohol and Drug Services Study (ADSS) was used, representing 109,973 methadone clients nationally. It was estimated that more than two-thirds of methadone clients nationally were receiving below 60 mg/day. While controlling for a number of client and organizational variables, a daily methadone dose of 60 mg/day or above was found to be associated with longer retention in treatment. Exploring factors affecting the utilization of the recommended daily methadone dose remains an important issue in effective delivery of methadone treatment.