Reliability of the "Parma Scale" for forensic psychiatric treatment evaluation: preliminary findings in a sample of prisoners with mental disorder

Objectives: Routine monitoring of treatment outcomes has been poorly implemented in Italian forensic psychiatric practice. This is also for lacking of reliable tools. Thus, the "Parma Scale"(Pr- Scale) was developed. The specific aim of this study was to examine the reliability of the Pr-Scale as preliminary investigation on its psychometric properties. Methods: Test-retest and interrater reliability was assessed in a sample of prisoners with mental disorder using Intra-Class Correlation (ICC) and stability coefficients. Internal consistency for the Pr-Scale total score was also calculated using the Cronbach alpha statistic. Results: Thirty male adult inmates with mental illness were recruited within the Parma Penitentiary Institute (PPI). Our results showed good to excellent interrater and test-retest reliability for the Pr-Scale scores, as well as an acceptable internal consistency for the Pr-Scale total score. Conclusions: The findings of this study seem to support the administration of the Pr-Scale in forensic psychiatric settings as reliable tool for routine monitoring of treatment outcomes. However, future studies to carefully investigate other crucial psychometric properties of the Pr-Scale (e.g. concurrent validity, sensitivity to measure scores' longitudinal changes, predictive validity for recidivism risk) are needed.