Clinical prediction rules can be derived and validated for injured Australian workers with persistent musculoskeletal pain: an observational study.

QUESTIONS Can clinical prediction rules be derived for injured Australian workers with persistent musculoskeletal pain? Are they valid? DESIGN Longitudinal observational study. PARTICIPANTS 847 injured workers with persistent musculoskeletal pain undergoing rehabilitation. OUTCOME MEASURES At baseline, 12 putative predictors were measured. At 9 weeks, short-term outcomes such as pain (visual analogue scale), activity limitation (Functional Rating Index) and work upgrade (increase in work hours or duties) were measured. At 6 months, long-term work status (working or not working) was measured. RESULTS Data were obtained from 85% of the participants who were followed up at both 9 weeks (720 of 847) and 6 months (247 of 290). Predictors of outcome included high baseline pain and activity limitation, long duration of previous intervention, not working, non-English speaking background, and the area of pain. Accuracy was highest for clinical prediction rules predicting pain and level of activity limitation at 9 weeks (R2 = 0.67 and 0.69 respectively) and work status at 6 months (LR- = 0.24). CONCLUSION Accurate clinical prediction rules have been derived and validated for injured workers with persistent musculoskeletal pain, predicting activity limitation, pain, and work outcomes following exercise-based rehabilitation. Further research to validate these prediction rules in other populations and to assess the effectiveness of tailoring intervention based on the estimated prognosis would be valuable.