Incidence and Mortality of Osteoporotic Fracture in Rheumatoid Arthritis in South Korea Using Nationwide Claims Data

BACKGROUND: To investigate incidence and mortaltiy of osteoporotic fractures (including hip, spine, distal radius, and proximal humerus) in rheumatoid arthritis (RA) patients and compare them with those in the genearal population. METHODS: Data provided by National Health Insurance Service were used to identify osteoporotic fractures in patients aged >50 years between 2010 and 2012. Patients with RA were identified by the diagnostic code for seropositive RA. Standardized mortality ratios (SMRs; observed/expected deaths) of osteoporotic fractures were calculated based on age and gender-specific rates in the entire Korean population. Incidence, mortality, and SMR of osteoporotic fractures in RA patients and the general population were calculated and compared. RESULTS: Osteopororic fractures in the general population and RA patients were increased by 11.6% and 17.4% over 3 years (195,271 and 1,356 in 2010; 217,985 and 1,592 in 2012), respectively. Mean age-specific incidence of osteoporotic fracture in women and men with RA increased from 932.1/100,000 and 306.1/100,000 for aged 50 to 59 year to 9,377.0/100,000 and 3,700.9/100,000 for aged ≥80 years, respectively. Cumulative mortality rate in the first year after osteoporotic fracture in patients with RA was higher than that in the general population (7.8% in RA and 6.6% in the general population). SMR of osteoporotic fracture in RA patients was 1.4 times higher in men and 1.3 times higher in women than that for the general population. CONCLUSIONS: This study demonstated that incidence, 1-year mortality, and SMR of osteoporotic fracture in RA patients aged 50 years and older were higher than those in the general papulation.