Risk Factors and Incidence of Repeat Osteoporotic Fractures Among the Elderly in Taiwan

The incidence of osteoporotic fracture (OF), a condition that leads to higher morbidity and mortality in the elderly, is increasing yearly worldwide. However, most studies of OF have focused on the epidemiology of initial fractures, mainly in female and white populations. This study aimed to explore the incidence and the risk factors for repeat osteoporotic fracture (ROF) in Taiwan.We performed a retrospective cohort study using the Taiwan National Health Insurance Database (NHIRD) from 1995 through 2011. Individuals aged 65 years or older who experienced an initial OF were included. The patients were followed until death, the end of registration in the NHIRD, ROF occurrence, or the end of the study period (December 31, 2011), whichever occurred first. The incidence of ROF over ≥ 5 years after the initial fracture was analyzed, and the risk factors for ROF were assessed using Cox proportional hazards models. The incidence rates of ROF were 950.5, 321.4, 158.7, 92.8, and 70.2 per 1000 person-years among subjects in their first, second, third, fourth, and fifth years after the initial OF, respectively. Nearly 45% of the subjects sustained a ROF in the first year after OF. ROF risk increased with age and Charlson Comorbidity Index (CCI) score. Greater risk for ROF was observed among female subjects and those who had suffered from hip and vertebral fracture at the first OF, had undergone OF-related surgery, and had received bone-related medications. The incidence of ROF in the Taiwanese elderly is higher during the first year after the initial OF, and ROF risk increases with age, female sex, high CCI score, and in those who have undergone OF-related surgery, sustained hip or vertebral fracture, and used bone-related medications.