Psychometric testing of the British-English Perceived Workplace Support Scale, Work Accommodations, Benefits, Policies and Practices Scale, and Work Transitions Index in four rheumatic and musculoskeletal conditions.

Objective: The aims were to validate linguistically British-English versions of the Perceived Workplace Support Scale (PWSS), Work Accommodations, Benefits, Policies and Practices Scale (WABPPS), and Work Transitions Index (WTI) in rheumatoid arthritis (RA), axial spondyloarthritis (axSpA), osteoarthritis (OA) and fibromyalgia (FM).

Methods: The three scales were adapted into British-English and reviewed by an expert panel prior to cognitive debriefing interviews. Participants completed postal questionnaires. Construct validity for the PWSS was assessed using Rasch analysis. Concurrent validity included testing between the three scales and work, job strain and work-life balance scales. Two weeks later, participants were mailed a second questionnaire to measure test-retest reliability.

Results: The questionnaire was completed by 831 employed participants: 68% women, 53.50 (SD 8.9) years of age, with condition duration 7.70 (SD 8.00) years. The PWSS satisfied Rasch model requirements. Concurrent validity was mostly as hypothesised, that is, weak to moderate negative correlations for the PWSS (r_s  = 0.07 to -0.61), and weak to moderate positive correlations for the WABPPS and WTI (r_s  = 0.20-0.52). Some correlations were stronger, mostly in axSpA. Internal consistency (Cronbach's alpha) for all three scales was consistent with group use in all conditions. Test-retest reliability was generally excellent, with intraclass coefficients (2,1) of 0.80-0.93 for the three scales in the four conditions.

Discussion: Reliable, valid versions of the British-English PWSS, WABPPS, and WTI are now available for use in research, organisational level studies and vocational rehabilitation.