We estimated the number of hip fracture patients in 2012 in Japan and investigated the trends in incidence during a 25-year period from 1987 to 2012. Despite the increasing number of patients, the incidence of hip fracture in both men and women aged 70-79 years showed the possibility of decline.
Introduction: The objectives of this study were to estimate the number of hip fracture patients in 2012, to investigate the trends in incidence during a 25-year period from 1987 to 2012, and to determine the regional differences in Japan.
Methods: Data were collected through a nationwide survey based on hospitals by a mail-in survey. Hip fracture incidences by sex and age and standardized incidence ratios by region were calculated.
Results: The estimated numbers of new hip fracture patients in 2012 were 175,700 in total (95 % CI 170,300-181,100), 37,600 (36,600-38,600) for men and 138,100 (134,300-141,900) for women. The incidence rates in both men and women aged 70-79 years were the lowest in the 20-year period from 1992 to 2012. The incidence was higher in western areas of Japan than that in eastern areas in both men and women; however, the difference in the incidence of hip fracture between western and eastern areas is becoming smaller.
Conclusions: Despite the increasing number of new patients, the incidence of hip fracture in both men and women aged 70-79 years showed the possibility of decline. The exact reasons for this are unknown, but various drugs for improving bone mineral density or preventing hip fracture might have influenced the results. A decrease in the differences in nutrient intake levels might explain some of the change in regional differences in Japan.
Keywords: Aging; Drug therapy; Hip fracture; Incidence; Osteoporosis; Time trends.