Clinically meaningful scores on pain catastrophizing before and after multidisciplinary rehabilitation: a prospective study of individuals with subacute pain after whiplash injury.

OBJECTIVES: Pain catastrophizing has emerged as a significant risk factor for problematic recovery after musculoskeletal injury. As such, there has been an increased focus on interventions that target patients' levels of catastrophizing. However, it is not presently clear how clinicians might best interpret scores on catastrophizing before and after treatment. Thus, the purpose of this study was to provide preliminary guidelines for the clinical interpretation of scores on pain catastrophizing among individuals with subacute pain after musculoskeletal injury.
METHODS: A sample of 166 occupationally disabled individuals with subacute pain due to a whiplash injury participated in this study. Participants completed a 7-week standardized multidisciplinary rehabilitation program aimed at fostering functional recovery. Participants completed the Pain Catastrophizing Scale (PCS) upon program commencement and completion. One year later, participants indicated their pain severity and involvement in employment activities. Separate receiver operating characteristic curve analyses were conducted to determine absolute pretreatment and posttreatment and percent change scores on the PCS that were best associated with clinically important levels of pain and employment status at the follow-up.
RESULTS: An absolute pretreatment PCS score of 24 best identified patients according to follow-up clinical outcomes. Posttreatment PCS scores of 14 and 15 best identified patients with high follow-up pain intensity ratings and those who did not return to work, respectively. PCS reductions of approximately 38% to 44% were best associated with return to work and low pain intensity ratings at follow-up. DISCUSSION: The results indicate scores on catastrophizing before and after treatment that are clinically meaningful. These results may serve as preliminary guidelines to assess the clinical significance of interventions targeting pain catastrophizing in patients with subacute pain after musculoskeletal injury.