Incidence and mortality of subsequent vertebral fractures: analysis of claims data of the Korea National Health Insurance Service from 2007 to 2016

BACKGROUND CONTEXT: Vertebral fracture is related to an increased risk for subsequent and recurrent osteoporotic fracture as well as increased mortality. However, no study has investigated the exact incidence and mortality of subsequent vertebral fractures. OBJECTIVE: The purpose of our study was to determine trends in the incidence and mortality of subsequent vertebral fractures after first-time vertebral fracture in Koreans older than 50 years using the national claims database. STUDY DESIGN: Retrospective cohort study. PATIENT SAMPLE: Data from the Korea National Health Insurance Service database from 2007 to 2016. OUTCOME MEASURES: The incidence of subsequent vertebral fracture during a 4-year follow-up period. The mortality and standardized mortality ratio (SMR) after subsequent vertebral fractures during the 1-year period after fracture were also determined. Analysis was restricted to patients older than 50 years. METHODS: The national claims data set was analyzed to find all new visits and revisits after 6 months from the last claim to a hospital or clinic for vertebral fractures and revisits in men and women aged 50 years or older between 2007 and 2016. The number of first-time vertebral fractures in 2012 was investigated to determine subsequent vertebral fractures. The incidence, mortality rates, and SMR of subsequent vertebral fractures were calculated. There were no sources of funding and no conflicts of interest associated with this study. RESULTS: During the 4-year follow-up period, the overall cumulative incidence of subsequent vertebral fractures were 27.53%. According to sex, the cumulative incidence of subsequent vertebral fractures was 20.09% in men and 29.98% in women. The cumulative mortality rate over the first year after subsequent vertebral fractures was 5%. The mortality rates over 1 year were 10.04% for men and 3.81% for women. The overall SMR at the 1-year follow-up after subsequent vertebral fractures was 10.58 (95% confidence interval: 9.29-12.05) in men and 3.88 (95% confidence interval: 3.5-4.3) in women. CONCLUSIONS: Our study showed that subsequent vertebral fractures were more common in women, with an incidence rate of 29.98% over 4 years. However, the mortality rate was higher in men, reaching 10.04% in 1 year. Subsequent vertebral fractures occurred in large numbers, and the mortality rates were relatively high. Thus, first vertebral fracture may be considered as an early warning of high risk for future subsequent vertebral fractures, especially in women. (C) 2019 Elsevier Inc. All rights reserved.