Development and psychometric properties of the Verona Service Satisfaction Scale for methadone-treated opioid-dependent patients (VSSS-MT).

We adapted the 32-item Verona Service Satisfaction Scale (VSSS-32) to assess opioid-dependent patient satisfaction with services received from methadone treatment centres. The preliminary version of the VSSS for methadone treatment (VSSS-MT) was filled out anonymously and completed by 516 randomly recruited patients. After exploratory factor analysis and item refinement, the definitive 27-item VSSS-MT accounted for 58.8% of the total variance, comprising four factors: Basic Interventions, Specific Interventions, Social Worker Skills, and Psychologist Skills. These factors showed good to excellent internal reliabilities (Chronbach's alpha: 0.91, 0.85, 0.87, and 0.92, respectively). At test-retest, intraclass correlation coefficients of VSSS-MT overall and factor scores were fair to good. The results of this study suggest that the VSSS-MT measures, briefly but also multidimensionally, opioid-dependent patient satisfaction with methadone treatment centres.