Trends in the incidence of secondary hip fractures and osteoporosis treatment in Japan (FY2012-FY2023).

Abstract

Introduction: This study aimed to clarify trends in the incidence of secondary hip fractures and pharmacotherapy after primary fractures over time in Japan.

Materials and methods: Using Japan's National Database of Health Insurance Claims and Specific Health Checkups, we examined the number of hip fracture patients and their osteoporosis medication status from fiscal year (FY) 2012 to FY2023.

Results: A total of 1,289,333 females and 312,968 males had primary fractures. Among them, 42,835 females and 8,249 males had a secondary fracture within 1 year following the primary fracture. The incidence rates averaged 3.44% annually, ranging from 3.26 to 3.57% by fiscal year. These rates showed an increasing trend from FY2012 to FY2018, followed by a decreasing trend until FY2020, but increased again in FY2021. The medication administration rate within the first year following the primary fracture progressively increased over time, from 39.1% in FY2012 to 49.6% in FY2021, followed by a notable increase to 65.5% in FY2022. Bisphosphonates were the most frequently administered medications, and the number of patients receiving bisphosphonates, eldecalcitol, denosumab, and romosozumab increased over time.

Conclusion: The medication administration rate has consistently increased. The incidence of secondary fractures decreased from FY2019 but then increased in FY2021 due to the impact of the coronavirus disease 2019 (COVID-19) pandemic. However, in FY2022, this increase was mitigated by the introduction of management fees. It is anticipated that the incidence of secondary fractures will decline again due to a further increase in medication rates following the COVID-19 pandemic.