The natural history of low back pain was evaluated over a nine year period in two groups of middle aged Dutch women selected from the general population. One group had recurrent back pain (n = 236) and the other group had never experienced back pain (n = 241). At the onset of the study recurrent back pain was associated with smoking, previous use of the 'pill', pain in other joints, frequent headaches, and restricted lumbar spine movement. Nine years later 170 (72%) of the group with back pain had continuing pain and 58 (24%) of the group without previous back pain had incident pain. Pain in other joints, especially the hip and knee, was a predictor of continuing and incident pain but age, body mass index, and smoking were not.
PIP: The correlates of back pain were analyzed by logistic regression in 2 groups of middle-aged Dutch women, 236 with recurrent back pain at the beginning of the study and 241 without; and followed, in the same subjects 9 years later. Subjects were selected from a population survey of rheumatic and cardiovascular diseases in Zoetermeer, the Hague, Holland, in 1975-1978. Initially they took a questionnaire, and had their height, weight, blood pressure, spinal movement and body mass recorded. In the follow up in 1985-1986 a questionnaire, lumbar spine radiographs, height and weight were taken. Initially a higher proportion of women with back pain had taken oral contraceptives, smoked, had cystitis, had frequent headaches currently, and other joint pain. Those with back pain and more limited spinal movement, less ability to do household tasks, 5.5% had changed jobs as a result of back pain, 54% had pain 3 months, and 46% had resorted to bed rest. At the follow up, those with back pain were more likely to use estrogens. 72% of those who initially had back pain still had it, compared to 24% of the initially pain-free now having back pain(relative risk 2.99). Continuing back pain was correlated only with pain in hip or knee, on univariate analysis and stepwise logistic regression. This is the 1st report of an association between use of oral contraceptives and recurrent back pain.