Confirmatory factor analysis of the work limitations questionnaire (WLQ-25) in workers' compensation claimants with chronic upper-limb disorders

Purpose: To examine the factorial validity of the Work Limitations Questionnaire (WLQ-25) among workers' compensation claimants with chronic upper-limb disorders. Methods: Attendees of the WSIB Shoulder and Elbow Specialty clinic in Toronto, Ontario, Canada, completed a survey that includes the WLQ-25 [4 subscales: time-management (TM), physical demands (PD), mental-interpersonal (MI), and output demands (OD)]. Confirmatory factor analyses (n = 2262) were conducted to evaluate and compare alternative 4- and 5-factor WLQ-25 structures [MI subscale intact vs. separated into mental demands (MD) and interpersonal demands (IP) subscales]. Model fit indices, saliency of factor loadings, and convergent/divergent validity of latent factors (r = 0.4 - 0.85 expected) were concurrently assessed. Results: The 4-factor WLQ-25 showed acceptable model fit after allowing the residuals of a pair of PD items to correlate (CFI = 0.924, TLI = 0.915, RMSEA = 0.057, SRMR = 0.054); however, significantly lower-than-expected correlations between the PD factor and all other factors (r = -0.11 - -0.03) were also observed. Model fit for the 5-factor WLQ-25 was even more optimal (CFI = 0.934, TLI = 0.925, RMSEA = 0.053, SRMR = 0.051), with MD and IP factors correlating at r = 0.83. Conclusions: Evidence of factorial validity was demonstrated by the WLQ-25; however, users should be attentive of an instrumentation issue that could be directly related to the psychometric performance of its PD subscale