Risk factors for sciatica leading to hospitalization

Purpose To study the known or suspected risk factors for sciatica: Tallness, overweight, smoking, leisure-time physical exercise, self-reported health and occupation, and how they predict hospitalizations due to sciatica. Only a few cohort studies have previously focused on the risk factors for sciatica. Methods The 13,095 subjects, free from low back disorders at the baseline in 1973–1976 were followed up to the end of 2011 via the Care Register for Health Care. Along with an invitation to the health examination, a basic questionnaire concerning lifestyle factors was sent to participants. The outcome measure was incident sciatica leading to hospitalization. Results Altogether 702 incident sciatica cases occurred. Among men, the adjusted hazard ratio (HR) with 95% confidence interval (CI) was 2.57 (95% CI 1.47–4.50) in metal or machine work, and 1.44 (1.06–1.95) in other industrial work, compared to that in white-collar occupations. Among women, the corresponding risk estimates were 1.81 (1.18–2.78) for nurses and related occupations, 1.56 (1.05–2.31) for sales workers, and 1.46 (1.03–2.08) for industrial workers. Among men, physical exercise during leisure predicted a decrease in the risk of sciatica (0.74; 0.55–1.00); this association was significantly pronounced in white-collar occupations (0.38; 0.18–0.88). Among women, the association between body mass index and the risk of sciatica was only modest, but varied greatly between different occupations. Conclusions Physically demanding work is a strong risk factor for sciatica. Leisure-time physical activity seems to protect men against sciatica, while overweight is a risk factor among women. However, occupation substantially modifies these associations.