Association between mortality risk and the number, location, and sequence of subsequent fractures in the elderly

Summary The mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk. Introduction It is unclear whether subsequent fractures or a certain location and sequence of subsequent fractures are associated with mortality risk in the elderly. We aimed to investigate the relationship between subsequent fractures and mortality risk. Methods Using the Korean National Health Insurance Research Database, we analyzed the cohort data of 24,756 patients aged > 60 years who sustained fractures between 2002 and 2013. Cox regression was used to assess the mortality risk associated with the number, locations, and sequences of subsequent fractures. Results Mortality hazard ratios (HRs) for women and men were shown to be associated with the number of subsequent fractures (one, 1.63 (95% confidence interval [CI], 1.48–1.80) and 1.42 (95% CI, 1.28–1.58); two, 1.75 (95% CI, 1.47–2.08) and 2.03 (95% CI, 1.69–2.43); three or more, 2.46(95% CI, 1.92–3.15) and 1.92 (95% CI, 1.34–2.74), respectively). For women, the mortality risk was high when hip (HR, 2.49; 95% CI, 1.80–3.44) or vertebral (HR, 1.40; 95% CI, 1.03–1.90) fracture occurred as a second fracture. Compared with a single hip fracture, there was a high mortality risk in the group with hip fracture after the first vertebral fracture (HR, 2.90; 95% CI, 1.86–4.54), followed by vertebral fracture after the first hip fracture (HR, 1.90; 95% CI, 1.12–3.22). Conclusion The mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk.