Effect of psychosocial factors on low back pain in industrial workers.

Aim: To test the hypothesis that workplace psychosocial factors such as demand, control, support, job satisfaction and job appreciation can predict the future onset of disabling low back pain (LBP).

Methods: The present study involved a prospective cohort of 4500 Iranian industrial workers. Data were gathered by means of a self-reported questionnaire about LBP, as well as working life exposure, lifestyle factors, social exposures, co-morbidity, life events and psychosomatic complaints in 2004. All new episodes of disabling LBP resulting in medically certified sick leave during the 1-year follow-up registered by occupational health clinic inside the factory.

Results: The participation rate was good (85%). A total of 744 subjects reported current LBP (point prevalence cases). A total of 52 (<2%) new episodes of disabling LBP were observed during the 1-year follow-up (incident cases). Male employees reported higher demands, lower control and lower support than female employees. Employees with high demands, low control, job strain, low job satisfaction and low job appreciation showed increased odds ratios, and these results were statistically significant.

Conclusions: Few prospective studies in this field have been published, but all of them are related to industrialized countries. This prospective study suggests the aetiological role of job strain for LBP. The findings of this study indicate a substantial potential for disease prevention and health promotion at the workplace.