Risk factors for subsequent hip fractures and fatality after an initial hip fracture in Korea: using nationwide claims data.

Abstract

The purpose of this study was to analyze the risk factors for subsequent hip fractures and fatality after an initial hip fracture among Koreans older than 50 years of age using information in the national claims database. Our study was conducted using data from the Korean National Health Insurance Service database from 2007 to 2016. A total of 16,915 Korean patients aged ≥ 50 years with a first hip fracture in 2012 were followed for 4 years. Data on fracture, comorbidity, and prescription variables were retrieved from the national registry. The Cox proportional hazards model was used to identify the risk factors affecting subsequent hip fractures and fatality after the initial hip fracture. A total of 952 patients had subsequent hip fractures, and 6793 patients died. The cumulative incidence rates were 1.3% after 1 year and 5.6% after 4 years. Old age, renal disease, dementia, and Parkinson's disease were associated with a higher risk of subsequent hip fractures. The fatality rate after the initial hip fracture was 1.6 times higher among men than among women. Certain risk factors for fatality, such as pneumonia after fracture, cerebrovascular disease, mild liver disease, renal disease, and malignancy, were more prevalent among men. During the study period, the risk of fatality after hip fracture but not the risk of subsequent hip fractures was higher among men. The gender difference in fatality might be explained by the larger burden of comorbid diseases among men.