There is limited evidence that contracts can potentially contribute to improving adherence, but there is insufficient evidence from large, good quality studies to routinely recommend contracts for improving adherence to treatment or preventive health regimens.
Contingency management of urinalysis results and intensity of counseling services have an interactive impact on methadone maintenance treatment outcome.
In a 3 x 2 factorial design, 360 new admissions to methadone maintenance were randomly assigned to one of three levels of counseling: (1) "medication only," (2) "standard" counseling, and (3) "enhanced" services; and one of two contingency contracting conditions: (1) no contingencies (NC), and (2) contingency contracting (CC). Contingency contracting included discharge for continuous positive urines; subsequently CC subjects were discharged at a greater rate than the NC group. However, CC subjects were more likely to be readmitted. NC subjects provided more urines positive for any illicit drug use than did CC subjects. For opiate positives a significant level of counseling by contingency contracting interaction was found with medication only/CC subjects obtaining fewer opiate positives than medication only/NC subjects. The impact of reduced or enhanced services and of contingency contracting will not be fully understood until longer term follow-up (18 and 24 month) is completed. Results suggest that contingency management procedures could be utilized in settings offering minimum services (e.g., "interim methadone") to achieve treatment outcomes similar to programs offering standard counseling services.