Influence of previous pain experience on the episode incidence of low back pain: results from the South Manchester Back Pain Study.

BACKGROUND: A pathological cause cannot be identified for most new episodes of low back pain (LBP) presenting to the general practitioner. One important potential influence on susceptibility is previous pain experience. To accurately investigate the contribution of this phenomenon to the onset of new episodes of LBP a prospective population study is required. AIMS: To determine the relationship of prior pain in the back and other musculoskeletal sites to risk of subsequent new episodes of LBP. METHODS: The population studied included all 2715 adults from the South Manchester Back Pain Study who were free of LBP during the month prior to the baseline survey. At baseline a detailed musculoskeletal pain history was obtained. New episodes of LBP over the subsequent 12 months were ascertained by: (i) prospectively monitoring all primary care consultations in the study cohort (consulting episodes) and (ii) a follow-up survey after 1 year to determine new episodes during that 12-month period not leading to consultation (non-consulting episodes). RESULTS: The 12-month cumulative incidence of new consulting episodes was 3% in males and 5% in females, and for new non-consulting episodes 31% in males and 32% in females. Those with a history of previous LBP had twice the rate of new episodes, both consulting and non-consulting, compared to those with no LBP in the past. Neck pain or pain in other musculoskeletal sites at baseline also doubled the risk of a subsequent new episode of LBP. Adjusting for psychological distress and the other pain variables had little influence on the findings. CONCLUSION: In those currently free of LBP a previous history of the symptom substantially increases the risk of a further episode, with pain in other sites an equally strong independent predictor of subsequent LBP.