Assessing discrepancies in outcomes of pain rehabilitation: "these questionnaires don't measure results that are relevant to me".

Background: Pain rehabilitation programs are recommended interventions for patients with chronic pain. Average effect sizes are moderate. Physiatrists, based on clinical experience, argue that the present outcome measures underestimate the outcome of pain rehabilitation programs. Objective: (1) To explore discrepancies and relationships in outcomes of pain rehabilitation. (2) To explore causes of discrepancies from the perspective of patients. Method: A mixed-method, prospective cohort study of patients who participated in pain rehabilitation programs. Outcome measures: Canadian Occupational Performance Measure, Pain Disability Index, a discharge assessment by the physiatrist. Differences and relations were tested. Semi-structured interviews about patients' explanations for discrepancy were performed via telephone. Results: Outcomes of 45/80 patients (56%) were discrepant. When discrepant, effect sizes of the Canadian Occupational Performance Measure and the Pain Disability Index were substantially lower, but the physiatrist-rated outcomes did not differ between discrepant and non-discrepant patients. Common patient-reported explanations for discrepancy were improvement of coping skills and irrelevant (items of) questionnaires. Conclusion: Discrepancies occurred often. When discrepant, physiatrist-rated outcome reflects a more positive outcome compared to the other outcome measures. The results of the interviews suggest that the present outcome measures may not fully capture life domains that are relevant for patients, and may thus underestimate meaningful outcomes.IMPLICATIONS FOR REHABILITATIONPresent standardized outcome measures may not fully capture and may underestimate meaningful outcomes of pain rehabilitation.Outcome measures of pain rehabilitation programs should include a meaningful patient-centered measure.Development of a patient-centered instrument to capture meaningful outcomes of pain rehabilitation is needed.