Trends in Hip Fracture Incidence in Japan: Estimates Based on Nationwide Hip Fracture Surveys From 1992 to 2017.

As of 2015, the aging population in Japan was the largest in the world. Although the National Database of Health Insurance Claims (NDB) was developed in 2012, long-term trends regarding hip fracture incidence in Japan remain unclear. In order to clarify the trend in hip fracture incidence from 1992 to 2017, we estimated the number of new hip fractures in 2017, the seventh in a series of nationwide hip fracture surveys performed every 5 years since 1987. We also investigated regional differences in hip fracture incidence. We collected data through a nationwide mail-in survey of orthopedic institutions in Japan and calculated hip fracture incidence by sex and age, as well as standardized incidence ratio (SIR) across 12 districts. The total number (95% confidence interval) of hip fractures in 2017 was estimated at 193,400 (187,300-199,500), occurring in 44,100 (42,700-45,500) males and 149,300 (144,500-154,100) females. Of all the hip fracture surveys from 1992 to 2017, the 5-year hip fracture increase rates from 2012 to 2017 was the lowest among female patients. In males, the 5-year rates from 2012 to 2017 were lower than those from 2007 to 2012. The age-adjusted incidence rates for patients in both sexes did not show significant change in the 25-year period. The estimated incidence rates in 2017 for patients aged 70 to 79 years in both sexes were lowest from 1992 to 2017, and declined significantly over the 25-year period. SIRs differed between northeast and southwest regions. Our findings were similar to those from a previous study in Japan using the NDB from 2012 to 2015. Progress in the development of osteoporosis medication may contribute to the continuous decline in the 70-year to 79-year age group.