Forensic Inpatient Observation Scale (FIOS): Development, Reliability and Validity

• NCJ Number: 195619
• Journal: Criminal Behaviour and Mental Health Volume: 11 Issue: 3 Dated: 2001 Pages: 144-162
• Author(s): Irma G. H. Timmerman; Nanette C. Vastenburg; Paul M. G. Emmelkamp
• Date Published: 2001
• Length: 19 pages
• Sale Source: NCJRS Photocopy Services
• Publication Format: Article
• Publication Type: Test/Measurement
• Language: English
• Country: United Kingdom

Annotation

This paper describes the development of the Forensic Inpatient Observation Scale (FIOS), an observation instrument to assess the non-offending functioning of forensic patients, as well as the testing of FIOS' reliability and validity.

Abstract

Recidivism as a measure of success in forensic psychiatry provides no information about other behaviors that may have changed as a result of treatment. FIOS was developed in an effort to measure some other significant behaviors. The development of the initial item pool of the BIOS resulted in an instrument that consisted of 78 items and 7 scales. The internal reliability of the scales ranged from 0.78 to 0.91. The inter-rater reliability of the scales varied from 0.50 to 0.85, and the test-retest reliability over a period of 3 weeks was high for most scales, ranging from 0.74 to 0.89. In the second study, the FIOS was developed further in another sample of forensic patients. Exploratory factor analysis with Varimax rotation and post hoc reliability analysis were applied to determine the factor structure among the items. This resulted in an item pool of 35 items, among which 6 factors could be distinguished that closely resembled the factor structure of the FIOS in the first study: self-care, social behavior, oppositional behavior, insight offense/problems, verbal skills, and distress. The internal consistency of the scales ranged from 0.73 to 0.91, and the scales appeared to be measuring independent constructs. Twenty-five out of the 35 items had an inter-rater correspondence of 90 percent or higher, and 30 out of 35 items had an inter-rater correspondence of 87.5 percent or higher. The inter-rater reliability on the scale level, however, was somewhat less satisfying with correlations that ranged from 0.50 to 0.69. The authors argue that training the observers regularly will improve the inter-rater reliability. There is some evidence for the convergent validity of the FIOS. The FIOS has some advantages over existing inpatient scales, in that it was developed specifically for forensic patients. It does not focus on axis 1 symptoms, but includes oppositional behavior and attitudes toward offending. 4 tables, 25 references, and appended FIOS