Evaluation of the predictive validity of the orebro musculoskeletal pain screening questionnaire

Objectives: To compare the predictive ability of the Orebro Musculoskeletal Pain Questionnaire-a screening tool for psychosocial factors in patients with low back pain across 2 cultural settings (Norway and Australasia) and to establish whether the Orebro provides additional information about outcome than that provided by the baseline value of the prognostic outcome. Methods: Prospective cohort studies with 12 month follow-up; 97 working patients were seeking primary care in Norway and 133 working individuals participated in a trial conducted in Australasia. A series of multiple regression analyses were conducted with pain and disability as outcomes, and the Orebro score and baseline values of the outcome as predictors. Results: The predictive ability of the Orebro was similar in Norway and Australasia in all the analyses except for disability at 12 months, in which the predictive ability was significantly stronger in Norway as compared to Australasia (P=0.011). The Orebro provided additional information about outcome than that provided by the baseline value of the prognostic outcome: for pain the R-square changes were from 2.4% to 4.0% with no statistically difference between the nationalities. For disability the R-square changes in the Australasian cohort ranged from 1.9% to 4.8% and in the Norwegian cohort from 4.5% to 6.5%. Discussion: The Orebro questionnaire had similar predictive ability in Norway and Australasia when pain was used as an outcome, whereas the Orebro tended to be a stronger predictor in Norway when disability was used as outcome.