Physical and psychosocial factors related to low back pain during a 24-year period - A nested case-control analysis

Study Design. A retrospective nested case-control study. Objectives. To identify occupational factors related to low back pain, and to study how interactions between psychosocial and physical factors, and be tween work-related and leisure-related factors affect low back pain in wome n and men. Summary of Background Data. A cohort of 484 subjects drawn from the general population was examined in 1969 and 1993, with a focus on occupational wor king conditions and musculoskeletal disorders. Methods. Information about the physical and psychosocial working conditions and low back pain during the period 1970 to 1993 was collected retrospecti vely. Odds ratios and confidence intervals were calculated for different po tential risk factors. Results. During the 24-year period, 46% of the subjects became patients wit h low back pain. Among women, heavy physical workload, sedentary work, smok ing, and the combination of whole-body vibrations and low influence over wo rk conditions were associated with an excess risk of low back pain. Among m en, excess risk for low back pain was seen in heavy physical workload, sede ntary work, high perceived load outside work, and the combination of poor s ocial relations and overtime. Conclusions. Factors at work were seen to be risk indicators for low back p ain among both genders. Low influence over work conditions among women and poor social relations at work among men, in combination with other factors, seem to be of high relevance for the occurrence of low back pain.