The pain disability questionnaire: Relationship to one-year functional and psychosocial rehabilitation outcomes

Objective: The Pain Disability Questionnaire (PDQ) is a new functional assessment instrument designed for evaluating chronic disabling musculoskeletal disorders. It is useful for assessing function/disability as affected by pain. This is the first study to assess the predictive validity of the PDQ in its relationship to 1-year post-treatment work- and health-related outcomes in a chronic disabling occupational musculoskeletal disorder (CDOMD) population. Design: A prospective cohort of CDOMD patients (n=150) completed a prescribed functional restoration rehabilitation program, with PDQ and other psychosocial measures evaluated before and immediately after treatment. A structured telephonic interview for objective work- and health-related outcomes took place 1-year following treatment. Results: Lower rates of work retention were associated with more severe pre-treatment PDQ scores. Higher post-treatment PDQ were associated with decreased return-to-work rates, decreased work retention and a greater percentage seeking health care from a new provider. In addition, PDQ scores were also associated with psychosocial measures such as depression and perceived pain intensity, as well as alternative measures of disability. Conclusions: Results demonstrated the ability of this simple and psychometrically-sound disability rating scale for systematic functional assessment in predicting treatment outcomes in patients with CDOMD. Results support the further use of the PDQ as a standard treatment outcomes measure in this area of musculoskeletal disorders.