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

Abstract

A retrospective nested case-control study. To identify occupational factors related to low back pain, and to study how interactions between psychosocial and physical factors, and between work-related and leisure-related factors affect low back pain in women and men. A cohort of 484 subjects drawn from the general population was examined in 1969 and 1993, with a focus on occupational working conditions and musculoskeletal disorders. Information about the physical and psychosocial working conditions and low back pain during the period 1970 to 1993 was collected retrospectively. Odds ratios and confidence intervals were calculated for different potential risk factors. During the 24-year period, 46% of the subjects became patients with low back pain. Among women, heavy physical workload, sedentary work, smoking, and the combination of whole-body vibrations and low influence over work conditions were associated with an excess risk of low back pain. Among men, excess risk for low back pain was seen in heavy physical workload, sedentary work, high perceived load outside work, and the combination of poor social relations and overtime. Factors at work were seen to be risk indicators for low back pain 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.