Trends in Osteoporotic Humerus Fractures and Refractures, and Mortality Rates: Analysis of NHIS Claims Data From 2006-2022.

BACKGROUND: Osteoporotic fractures have become a significant public health concern due to their high prevalence and associated morbidity and mortality. Humerus fractures, specifically, have gained attention as they are the third most common type of osteoporotic fracture. However, there is limited research on the trends and outcomes of humerus fractures, as well as the rates of refractures and mortality in this population. METHODS: This study aimed to analyze claims data from the National Health Insurance Service from 2006 to 2022 to investigate the trends in osteoporotic humerus fractures, refractures, and mortality rates in Korea. The study included all individuals aged 50 years and older who were diagnosed with a humerus fracture and had available data for one-year outcome ascertainment. Statistical analysis was performed to determine the incidence rates, trends over time, and associated mortality rates. RESULTS: Among 197,086 humerus fracture cases, incidence increased sharply from 2006-2010 then plateaued through 2022. Female predominance was consistent at 2.5-fold throughout. One-year mortality improved in females, with standardized mortality decreasing from 9.6% to 5.5% during 2006-2021, but remained approximately 2-fold higher in males. Advanced age was the strongest predictor of mortality, with hazard ratios increasing exponentially from 2.19 at age 60 to 11.53 at age ≥ 85. Refracture rates increased 4-fold in females (17 per 1,000 to 67 per 1,000 from 2007-2021), with higher rates in younger age groups. Most strikingly, pronounced socioeconomic disparities persisted: Medical Aid beneficiaries showed the highest fracture incidence, approximately 2-fold higher than the highest workplace insurance group, with some years approaching 2.5-fold. A socioeconomic gradient was most evident among regional insurance beneficiaries and was more attenuated among workplace insurance beneficiaries. CONCLUSION: This comprehensive analysis demonstrates that advanced age is an important determinant of one-year mortality after humerus fracture, whereas lower socioeconomic status is associated primarily with higher fracture incidence. The persistently high refracture rate through 2021 underscores the need for improved secondary fracture prevention and fracture referral services.