Annual Incidence of Hip Fractures in Nagasaki, Japan (Trends from 2005 to 2019): A Retrospective Observational Study

Background Hip fracture, a major osteoporotic fracture, is associated with a reduced quality of life. This study aimed to assess the current status and features of hip fractures in Nagasaki Prefecture, Japan. Methods Hip fractures reported in Nagasaki Prefecture between 2005 and 2019 were evaluated based on emergency transportation records. Data on the number of occurrences and incidence were analysed by age, sex, fracture type, month, day of the week, and recognition time to determine the actual situation and risk factors for hip fracture. Results The total number of new hip fractures among patients aged ≥ 35 years was 27,331 (mean age, 83.5 years), with the annual incidence per 100,000 persons increasing from 147.7 in 2005 to 237.3 in 2019. Women (79.3%) were more often affected than men (20.7%). Compared with trochanteric fractures, cervical fractures were more common in all age groups. However, the proportion of trochanteric fractures increased annually. Hip fractures tended to be associated with advanced age (≥ 80 years), winter season, and indoor settings. They were more frequent in the living room rather than in the bathroom or toilet on Mondays and during the early hours of the morning. Seven days post-admission, 97.1% of patients were still hospitalised, and 79.7% of the hip fractures had been surgically treated. Conclusions Data on the actual situation and characteristics relevant to hip fractures are urgently required for establishing effective preventive measures.