Headache in Sweden: the importance of working conditions

Headache is a common health problem that causes individual suffering as well as public expense. Because epidemiological studies have shown that headache is most prevalent among persons younger than 55 years, the influence of working conditions is of interest. In this study, we examined the importance of working conditions as a risk factor for frequent headache among the general Swedish population. Data from the Swedish Survey of Living Conditions for the 2-year period, 1988 and 1989, were used. In this survey, a probability sample of the Swedish population aged 16 years and older was interviewed. Frequent headache was defined as a positive answer to the question, "Have you (during the last 2 weeks) had recurrent headache or migraine?" Work stress was studied for two indices: physical work stress and mental work stress. The physical work stress index contained measurements of seven working conditions, and the mental work stress index contained measurements of three working conditions. The proportion of persons who reported frequent headache was greater among women than men, and frequent headache was most common in the age group 25 to 44 years. The logistic regression analyses showed that both physical and mental work stress were strongly associated with frequent headache among both men and women even after controlling for potential confounders. The associations between work stress and frequent headache may be dose-dependent. Heavy mental work stress was most strongly associated with frequent headache among men (odds ratio 3.03 [1.92 to 4.78]) while heavy physical work stress was most strongly associated with frequent headache among women (odds ratio 3.48 [1.13 to 10.65]). Improved working conditions could be one way of preventing headache, thereby decreasing individual suffering and employer as well as public expense.