Length of sick leave as a risk marker of hip fracture: a nationwide cohort study from Sweden.

Abstract

Sickness absence is a risk marker for future health outcomes, but no previous studies have examined its association with osteoporotic fractures in old age. The results of this prospective population-based cohort study based on Swedish registers suggest that sickness absence is associated with higher risk of hip fracture. Number of sick leave days is a risk marker for future health outcomes, but few studies have examined its association with major public health concerns in old age, such as osteoporotic fractures. The aim of this prospective, nationwide, population-based cohort study based on Swedish registers was to investigate the association between number of sick leave days and future risk of hip fracture. Participants included were all 983,244 individuals who were living in Sweden on 31 December 1995, aged 50 to 64 years, employed, and with no previous hip fracture. Those with sick leave days in 1995 were compared to those with no sickness absence. Incidence of hip fracture was followed from 1996 to 2010. According to Cox regression models adjusted for sociodemographic factors and morbidity, being on sick leave more than 3 months, irrespective of cause, was associated with a 2.0-fold (hazard ratio (HR) 1.96, 95% confidence interval (CI) 1.74-2.20) and 1.4-fold (HR 1.40, 95% CI 1.27-1.56) increased risk of hip fracture in men and women, respectively. Analyses repeated among those with previous non-hip fractures replicated the significant associations. This nationwide cohort study suggests that sickness absence in working-age women and men is a risk marker of hip fracture at old ages.