Is smoking and alcohol consumption associated with long-term sick leave due to unspecific back or neck pain among employees in the public sector? Results of a three-year follow-up cohort study.

Objective: To investigate the associations between smoking and alcohol consumption, and long-term sick leave due to unspecific back or neck pain among employees in the public sector.

Design: A 3-year prospective cohort study.

Subjects: Approximately 9000 persons in the public sector in Sweden were invited to participate. Of these, 7533 answered a questionnaire and 6532 were included in the study, classified as having "good health for working".

Methods: New periods of sick leave >or= 28 days were consecutively reported from the employers or the occupational health service during a period of 3 years. Rate ratios were estimated by means of Cox proportional hazard regression model.

Results: Smoking was associated with an increased risk of long-term sick leave due to unspecific back or neck pain. Compared with people who have never smoked, "ever smokers" had a higher risk (rate ratio = 1.8, 95% confidence interval: 1.3-2.4). Alcohol consumption tended to be associated with a decreased risk, but the results were not statistically significant.

Conclusion: Our results suggest that smoking is a risk factor for long-term sick leave due to unspecific back or neck pain. Moderate alcohol consumption tends to have a protective effect, at least among women in the public sector.