Background and Purpose. This study estimated the Roland-Morris Back Pain Questionnaire's (RMQ) change score that best classified patients as those who had achieved an important change and those who had not achieved an important change. The study also investigated whether the estimate of change was dependent on patients' initial scores. Subjects and Methods. The RMQ was administered to 226 patients with low back pain of less than 6 weeks' duration during their initial visit for physical therapy and following 3 to 6 weeks of treatment. A global rating of change was used to classify patients as those who had changed an important amount and those who had not changed. Receiver operating characteristic curves were used to identify the RMQ change score that most accurately classified patients with respect to important change. This analysis was repeated for 5 overlapping subsamples of patients with initial scores 0 to 8, 5 to 12, 9 to 16, 13 to 20, and 17 to 24. Results. The area under the receiver operating characteristic curves increased when patients' initial scores were taken into account. Estimates of important change were 2, 4, 5, 8, and 8 for the initial score intervals mentioned above. Conclusion and Discussion. Important change appears to be dependent on patients' initial RMQ scores. Subsequent inquiry using different hypotheses would add support to the estimates of important change found in this study.


Key Words:
  • Received July 7, 1997.
  • Accepted May 19, 1998.