Psychometric Properties of the Worker Role Interview (Version 10.0) in Mental Health

Abstract

Introduction: Occupational therapists working in psychiatry are routinely required to undertake vocational assessments and to support clients into work. To make such efforts successful, the use of evidence-based practice and outcome measures is becoming increasingly important. Objectives: The objectives were to examine the psychometric properties of the Worker Role Interview (WRI, version 10.0) with a psychiatric population in the United Kingdom, particularly its construct validity as a baseline assessment and an outcome measure. Method: Data were collected from 34 psychiatric clients rated by seven occupational therapists. Rasch analysis was used to examine scale validity, validity of therapists' rating patterns of clients, rater consistency, precision of client measurement and the scale's aptitude in detecting different ability levels. Results: All items except one demonstrated acceptable goodness-of-fit to the Rasch model. Over 90% of clients fitted the model. The scale detected five ability levels, but client measures were slightly imprecise. Raters used the scale consistently and implications of rater leniency are discussed. Conclusion: The study provides evidence of construct validity, supporting the use of the WRI as a standardised baseline assessment in a mental health population. Further development of the WRI might be indicated and its usefulness as an outcome measure should be tested with larger samples.