Internal consistency and construct validity of the Revised Illness Perception Questionnaire adapted for work...

To assess internal consistency and construct validity of the French version of the Revised Illness Perception Questionnaire adapted for Work Disability (IPQR-WD).

A cross sectional study was conducted in rehabilitation centers and private clinics in the Montreal region of Canada, involving 43 men and women, French speaking, absent from work between 3 months and a year due to musculoskeletal disorders. The 9 dimension IPQR-WD and the following eight-related instruments for construct validity were administered: Tampa Scale for Kinesiophobia (TSK), Pain Catastrophizing Scale (PCS), Psychological Distress Index (PDI-14), Pain Disability Index (PDI), Self-Efficacy for Return to Work Scale (SERWS), Pain Beliefs and Perceptions Inventory (PBPI), Implicit Models of Illness Questionnaire (IMIQ) and a Visual Analog Scale for pain intensity (VAS).

Calculations of Cronbach's α (from 0.58 to 0.87) revealed satisfactory internal consistency of the IPQR-WD dimensions. Multiple regression analyses were performed with each IPQR-WD dimension and significant independent variables. Final models explained a good proportion of the variance (adjusted r(2) = 0.33-0.70) for each dimension, except for the Cyclical timeline dimension for which associations became non-significant after adjusting for gender, age and length of sick leave. The SERWS and the VAS were not significantly associated to any of the IPQR-WD dimensions.

Moderate to strong correlations were found with six-related instruments which support the multidimensional nature of the IPQR-WD and its unique contribution as one simple questionnaire that can assess representations related to work disability. [Box: see text].