Medical, psychological, and social factors associated with back abnormalities and self reported back pain: a cross sectional study of male employees in a Swedish pulp and paper industry.

A medical, psychological, and sociological study of 391 male employees in a Swedish pulp and paper industry was performed in 1961. Factors associated with back pain and back abnormality were investigated. Univariate analyses showed associations of back pain with occupational status, low education, duration of employment, low performance on cognitive tests, and neuroticism. Back abnormalities evaluated on the basis of physical examination showed in principle the same associations but the strength as well as the significances were stronger. Multiple logistic regression analyses using data for manual workers showed that neuroticism and duration of employment were directly associated with back pain. The same two variables and low performance on one of the psychological tests were directly associated with back abnormalities. Age showed no direct association with back pain or back abnormalities. Strong associations between back pain and back abnormalities with both perceived health and general working capacity and the doctor's evaluation in the same areas were demonstrated.