Incidence and Mortality of Osteoporotic Refractures in Korea according to Nationwide Claims Data

Abstract

Purpose: Studies on the incidence and mortality of refractures after primary osteoporotic fracture are limited by the relatively rare incidence of such refractures and small sample sizes. The objectives of this research were: 1) to determine the incidence of osteoporotic refractures and fracture locations and 2) to assess mortality rates associated with osteoporotic refracture over a median follow up of 3 years using nationwide claim database. Materials and Methods: Patients over 50 years of age who had an osteoporotic fracture that was confirmed operationally were enrolled. Refracture was defined as that after 6 months of an untreated period. Mortality rate was calculated using the Charlson comorbidity index and was analyzed using Cox proportional hazards regression analysis. Results: A total of 18956 first-time instances of osteoporotic fracture were reported between 2007 and 2012 after a median follow up of 3.1 years (range, 1 to 7 years). Among 18956 patients, 2941 (15.50%) experienced refracture. After follow up for 1 year, cumulative mortality rates for re-fracture and non-refracture groups were 9.1% and 7.2%, respectively. After adjusting for covriates, mortality rate was 1.2 times greater in patients with re-fracture than in patients without re-fracture over a median follow up of 3 years (hazard ratio: 1.20, 95% confidence interval: 1.08-1.34, p<0.001). Conclusion: The incidence of osteoporotic re-fracture in this nationwide study was 15.5%, and the mortality rate of re-fracture patients was 1.2 times higher than that of non-refracture patients over a median follow up of 3 years.