Assessing Dimensionality and Responsiveness of Outcomes Measures for Patients with Low Back Pain

Objective: To provide a systematic literature review of the responsiveness of patient- reported health outcomes measures for the evaluation of low back pain (LBP). Methods and Design: Searches of MEDLINE and EMBASE were performed for articles published in English through June 29, 2009 using the search terms "back pain" or "low back pain" and "questionnaires" or "instrument" or "survey" or "measure" or "patient report outcome." Information on responsiveness was gathered through additional measure-specific searches that included the measure name, first author of the original paper, and "respons*" or "sensit*." Responsiveness was determined based on use of a receiver operating characteristics curve or effect size statistics. Results: Of 43 identified measures, 31 were reported as being responsive to treatment or clinical change, 25 of which were evaluated for responsiveness using methods considered adequate. When considering both the responsiveness evaluation and the underlying factor structure, 13 measures were identified as being adequately validated for use in evaluating responsiveness in the research or clinical practice setting. The majority of the LBP outcome assessment studies were comprised of patients undergoing physical and interventional therapies from clinical practice and clinical trials. The Roland Morris Disability Questionnaire and the Oswestry Disability Index were the most comprehensively validated measures with respect to responsiveness. Conclusions: We identified 13 measures of LBP that can be used to evaluate responsiveness to change. Choice of a measure warrants careful evaluation of its construct and responsiveness properties in order to maximize the observed impact on pain and functional improvement in subjects with LBP.