EMPLOYMENT AND PHYSICAL WORK ACTIVITIES AS PREDICTORS OF FUTURE LOW-BACK-PAIN

Study Design. A population-based longitudinal study conducted in north west England for a 12-month period involving adults aged 18-75 years. Objectives. To determine physical factors related to employment that p redict a new episode of low back pain. Summary of Background Data. Mos t epidemiologic studies that have examined the relation between occupa tion and back pain have been cross-sectional or retrospective in desig n. Because workers who have experienced low back pain may have changed jobs or work activities, it is important to use longitudinal studies that define ''exposures'' before the onset of symptoms. Methods. From adults registered with two general practices in northwest England, 141 2 people who were currently in employment and free of low back pain we re identified. A lifetime occupational history was recorded for all pa rticipants, with details of activities performed in each occupation. D ata on consultations for low back pain during the follow-up year were collected th rough computerized medical records, whereas those who had not consulted with low back pain were sent another questionnaire at t he end of the 1-year follow-up. Results. An increased risk of a new ep isode of low back pain was found in those whose jobs involved lifting/ pulling/pushing objects of at least 25 lbs, or whose jobs involved pro longed periods of standing or walking. Risks were, in general, greater in women, for a first ever episode of back pain and for back pain tha t led to a general practice consultation. No clear relation between ye ars of exposure to such factors and magnitude of risk was evident. Con clusions. Occupational activities, particularly in women, such as work ing with heavy weights or lengthy periods of standing or walking, were associated with the occurrence of low back pain. Short-term influence s may be more important in the occurrence of new episodes rather than cumulative lifetime exposure, and emphasize that such morbidity may be avoidable.