Predictors of back pain in a general population cohort

Study Design. The study used longitudinal data from the first and second cycles ( 1994 - 1995 and 1996 - 1997) of the Canadian National Population Health Survey. Objective. Our objective was to derive prediction models for back pain in the general male and female household populations. Summary of Background Data. Little is known about the predictors of back pain in the general population. Most previous studies focused on specific occupational groups and used a cross- sectional or case- control design. Methods. The study cohort consisted of all respondents aged 18 + years who reported no back problems in the 1994 - 1995 National Population Health Survey cycle ( N = 11,063). Potential predictors of chronic back pain were classified into nine groups and entered into stepwise logistic regression models. Bootstrap methods were used to derive the final models and assess their predictive power. Results. The overall incidence of back pain was 44.7 per 1,000 person- years and was higher in women ( 47.0 per 1,000 person- years) compared with men ( 42.2 per 1,000 person- years). In men, significant predictors of back pain were age ( peak effect in 45 - 64 years), height, self-rated health, usual pattern of activity ( especially heavy work), yard work or gardening ( negative association), and general chronic stress. In women, significant factors were self- reported restrictions in activity, being diagnosed with arthritis, personal stress, and history of psychological trauma in childhood or adolescence. Conclusions. Overall health and psychosocial factors are important predictors of back pain in both men and women. Other risk factors differ between the two sexes.