Chronic back pain in patients with rheumatoid arthritis and in a control population: prevalence and disability--a 5-year follow-up.

OBJECTIVES: To determine the prevalence of chronic back pain and its changes over 5 years in patients with RA compared with community controls and to evaluate the influence of chronic back pain in functional capacity, general pain and global health.
METHODS: The prevalence of chronic back pain in 1076 patients with RA and in 1491 community controls was evaluated using a mailed questionnaire, which also queried the functional capacity on the HAQ, and general pain and global health on visual analogue scales.
RESULTS: Chronic back pain was more frequent in the general population than in patients with RA: 19% of patients with RA and 25% of controls reported chronic back pain (P < 0.001). After 5 years, 57% of these patients initally reporting pain and 58% of controls still reported chronic back pain. In community controls with and without chronic back pain, the median HAQ, general pain and global health were 0.13 vs 0.00, 28 vs 6 and 28 vs 11, respectively (P < 0.001). The figures were 0.88 vs 0.63 (P = 0.05), 42 vs 26 and 42 vs 30 (P < 0.001), respectively, in patients with RA. All analyses were adjusted for age and sex.
CONCLUSION: Chronic back pain does not occur more frequently in patients with RA than in the general population. Almost 60% of patients and controls who reported chronic back pain still reported it 5 years later. In patients with RA and in the control population, subjects with chronic back pain had worse functional capacity, general pain and global health.