Back pain distribution patterns: relationship to subjective measures of pain severity and disability.
OBJECTIVE: To investigate the relationship between subjective pain measures and clinical subgroupings as determined by pain distribution patterns in back pain patients. DESIGN: A prospective study using a computer-interview system. SETTING: The Anglo-European College of Chiropractic outpatient clinic. PATIENTS: Two hundred fourteen new patients with low back pain completed the computer back pain interview on their first or second visit to the clinic. No other inclusion criteria were applied. MAIN OUTCOME MEASURES: Computer versions of the VAS, Oswestry and St. Thomas' disability questionnaires and the pain drawing. RESULTS: Back pain patients with pain radiating below the knee (Group 3 patients) reported significantly higher levels of disability than patients with back pain alone (Group 1 patients) (p < .001) and back pain with pain referred to the buttock/thigh region (Group 2 patients) (p < .01). Similarly, Group 3 patients reported significantly higher levels of pain severity than both Group 1 (p < .01) and Group 2 (p < .05) patients. The increased level of disability reported by Group 3 patients almost exactly matched the increase in self-assessed pain severity. No differences were observed in the report of either pain severity or disability between Group 1 and Group 2 patients. CONCLUSION: Subjective pain measure scores were shown to be related to recognizable clinical subgroupings of back pain based on the distribution, but not the extent, of the patient's pain. Back pain patients with radicular pain below the knee were found to be a high disability/pain severity group compared with other groups of back pain patients. More work is needed to investigate the potential of subjective pain measures in the differential diagnosis of back pain syndromes.