The Instrument for Forensic Treatment Evaluation: Reliability, Factorial Structure, and Sensitivity to Measure Behavioral Changes

ABSTRACT

Routine Outcome Monitoring (ROM) is widely used in general mental health care but is still in its infancy in forensic psychiatry. As usable forensic ROM tools are lacking, the Instrument for Forensic Treatment Evaluation (IFTE) has been developed. The goal of this study is to assess the psychometric values of the IFTE and its ability to assess change. Therefore, multiple IFTE assessments of 218 male forensic inpatients were gathered, after which the interrater reliability, test–retest reliability, and internal consistency were assessed. Principal axis factoring was assessed to examine the clinically used factor structure. Patient scores were divided into low and high IFTE factor scores at T0 to examine changeability between T0 and T3. The results display moderate to good values for the interrater reliability, test–retest reliability, and internal consistency for most items. Factor analyses partly confirmed the original factor structure of the instrument. However, several items loaded on a fourth factor. The factor scores display a moderate to large change over time. These results mostly support the clinical use of the IFTE in treatment. However, sexually deviant behavior should be studied in a less structured setting. Future studies would have to assess the use of the IFTE in supporting treatment decisions and its use in individual treatment.

KEYWORDS:

• Forensic psychiatry
• routine outcome monitoring
• reliability
• treatment evaluation