The psychometric properties of the German version of the new worker role interview

Objective: Occupational therapists play an important role in work rehabilitation in getting people with chronic disabilities back to work. The Worker Role Interview (WRI) is intended to detect psychosocial and environmental factors influencing the ability to return to work for injured or disabled workers. This study examined the psychometric properties of the recently modified German version (WRI-G, 10.0) in a population with work-related musculoskeletal disorders (MSD) in Switzerland. Methods: Data were gathered from 20 participants with work-related MSD. The interviews were conducted face-to-face and videotaped. Five occupational therapists, trained in the use of the WRI-G, independently rated all 20 interview recordings following the official manual. Thus, 100 ratings were analysed by use of Rasch analysis to test construct validity and transform ordinal raw data into linear data (person locations) for interrater-reliability calculations. Results: All items fit the Rasch model, except the item 'perception of boss'. The final WRI-G, consisting of 15~items, showed good overall model fit (X^{2} = 54.66, p= 0.04); excellent person-separation reliability (PSI 0.91) and high inter-rater reliability (mean ICC 0.90). Conclusions: Based on this sample, the WRI-G (10.0) is a valid and reliable instrument to assess psychosocial ability for return to work in a population with work-related MSD