Subsequent fracture rates in a nationwide population-based cohort study with a 10-year perspective

Fractures after the age of 50 are frequently observed in Denmark, and many of these may be osteoporotic. This study examined the incidence of all and subsequent fractures in a 10-year period from 2001 to 2011. The incidence of subsequent fractures was high, especially following hip fracture. The purpose of this study is to examine patterns of subsequent fractures and mortality rates over a 10-year period in patients already suffering from fracture. The study was designed as a nationwide, register-based follow-up study. Patients were included if diagnosed with an index fracture (ICD-10 codes: S22.x, S32.x, S42.x, S52.x, S62.x, S72.x, S82.x, S92.x, T02.x, T08.x, T10.x and T12.x) between January 1st, 2001 and December 31st, 2001 and if older than 50 years at time of fracture. The patients were investigated for future subsequent fractures from January 1st, 2002 to December 31st, 2011. In this study, we demonstrated that patients with fractures (especially hip fractures) have a high risk of subsequent fractures, especially hip fracture. Other fractures, which are not commonly considered as osteoporotic fractures, such as lower leg, were frequently observed in the 10 years following index fracture. The cumulative incidence proportion (CIP) of subsequent fractures during the 10-year follow-up period was high for all recurrent fractures (9-46 %). Subsequent hip fracture, regardless of index fracture, had the highest CIP across the study period, ranging from 9 to 40 %. Appendicular fractures were often followed by a recurrent fracture, or subsequent fractures at a more proximal location in the same limb, i.e. forearm fractures were followed by humerus fractures. These results have not been previously demonstrated to this extent, and according to our knowledge, no previous studies have estimated cumulative 10-year subsequent fracture incidences for any non-hip fractures. Patients suffering a fracture (and especially a hip fracture) have a high incidence of subsequent fracture. Fractures after the age of 50 may be considered an early warning of increased risk for future fractures in many patients.