Risk factors for recurrent episodes of work-related low back disorders in an industrial population

Study Design. An observational longitudinal design. Objectives. To characterize the rate of and risk factors for recurrent episodes of work-related low back disorder in industrial workers. Summary of Background Data. Little data exist on risk factors for recurrent episodes of work-related low back disorders in employed persons. Methods. A total of 352 active hourly union employees who were diagnosed with a recent work-related low back disorder and who had at least one follow-up visit within 12 months enrolled for participation in a rehabilitation intervention study at the workplace. Information on clinical and job factors was obtained at each study visit. Job risk for low back disorder was quantified using the Lumbar Motion Monitor. The main outcome measure, recurrence of work-related low back pain, was derived from a computerized file of administrative records of visits to the plant's medical department. Results. The rate of repeated episodes was 24.4%; an additional episode occurred in 2.3%. Adjusting for age, gender, health status and job exposures, lower levels of physical health, increasing back pain disability, spinal deformity, high stress, and increasing number of different jobs worked at the same plant were risk factors for a recurrent episodes of low back pain. Conclusions. Early identification of risk factors for a work-related low back disorder may signal the need for early and intense rehabilitation to prevent recurrent episodes. Because these findings were based on jobs with medium risk of low back disorders, other factors may be significant in higher risk jobs.