A prospective study of fatal occupational accidents -- relationship to sleeping difficulties and occupational factors.

Very little is known about the association between sleep and (fatal) occupational accidents. This study investigated this relationship using register data of self-rated sleep difficulties, together with occupational and demographic characteristics. The variables were related to subsequent occupational fatal accidents. A national sample of 47,860 individuals was selected at regular intervals over a period of 20 years, and interviewed over the phone on issues related to work and health. The responses were linked to the cause of death register (suicides excluded) and the data set was subjected to a (multivariate) Cox regression survival analysis. One hundred and sixty six fatal occupational accidents occurred, and the significant predictors were: male vs. female: relative risk (RR)=2.30 with a 95% confidence interval (CI) of 1.56-3.38; difficulties in sleeping (past 2 weeks): RR=1.89 with CI=1.22-2.94; and non-day work: RR=1.63 with CI=1.09-2.45. No significant effect was seen for age, socio-economic group, hectic work, overtime (>50 h per week), or physically strenuous work. It was concluded that self-reported disturbed sleep is a predictor of accidental death at work, in addition to non-day work and male gender.