Incidence and recurrence of disabling low back pain and neck-shoulder pain.

STUDY DESIGN: A prospective cohort study with 1-year follow-up.

OBJECTIVES: To assess incidence and recurrence of disabling low back (LBP) and neck-shoulder pain (NSP) in an industrial population, and to investigate the association with sex and job title during follow-up.

SUMMARY OF BACKGROUND DATA: Epidemiologic data of LBP and NSP are sparse from developing countries.

METHODS: All employees (18,031) in an Iranian industry were invited to participate in a baseline survey and followed for 1 year regarding new episodes of sickness absence due to LBP or NSP (disabling pain).

RESULTS: The 1-year incidence of disabling LBP was 2.1% and of NSP 0.1%. Although the prevalence of LBP in females was higher than in males, the incidence disabling LBP were higher in males. Both prevalence and incidence of disabling LBP were high in unskilled workers. For NSP, managers had the highest reported prevalence, but incident cases happened only among office workers and unskilled workers.

CONCLUSIONS: The incidence, especially for NSP, is much lower than from developed countries. To study prevalence, incidence and recurrence of LBP and NSP simultaneously leads to a better understanding of the natural pattern and distribution of LBP and NSP in a working population.