The reliability of determining “leg dominant pain”

Abstract Background context Patients with back dominant pain generally have a worse prognosis after spine surgery when compared with patients with leg dominant pain. Despite the importance of determining whether patients with lumbar spine pain have back or leg dominant pain as a predictor for success after decompression surgery, there are limited data on the reliability of methods for doing so. Purpose To assess the test-retest reliability of a patient's ability to describe whether their lumbar spine pain is leg or back dominant using standardized questions. Study design/setting Prospective, blinded, test-retest cohort study performed in an academic spinal surgery clinic. Patient sample Consecutive patients presenting for consultation to one of three spinal surgeons for lumbar spine pain were enrolled. Outcome measures Eight questions to ascertain a patient's dominant location of pain, either back dominant or leg dominant, were identified from the literature and local experts. Methods These eight questions were administered in a test-retest format over two weeks. The test-retest reliability of these questions were assessed in a self-administered questionnaire format for one group of patients and by a trained interviewer in a second group. Results The test-retest reliability of each question ranged from substantial (eg, interviewer-administered percent question, weighted kappa=0.77) to slight (eg, self-administered pain diagram, weighted kappa=0.09). The Percent question was the most reliable in both groups (self-administered, interviewer). All questions in the interviewer-administered group were significantly (p