[Incidence of hip fracture and prognosis in Ehime Prefecture]

Hip fracture among the elderly has increasingly attracted public health concern in Japan. For the purpose of revealing the epidemiological features of hip fracture, post-treatment prognosis, and related factors, we studied all cases of hip fracture which occurred in Ehime Prefecture during 1992 who were admitted to hospitals or clinics, and followed up the cases for a subsequent two years. The incidence rate of hip fracture was 29.2 per 100,000 for males, and 84.0 for females, which are much lower than in Europe and the Untied States. Compared with rates reported previously in Japan, the age--specific incidence rates for males in Ehime were almost identical to the respective rates estimated by a nationwide survey and the rates for Tottori. However, the rate for males 80 years old or more was found to be lower than the corresponding rate for Kagawa. In females, the age--specific incidence rates for Ehime were similar to the Japanese averages, and the rates for Tottori and Kagawa. Falling from a standing position was a leading cause of hip fracture among older patients. Osteosynthesis was the main treatment modality elected trochanteric fractures. On the other hand, prosthetic replacement was predominant in cervical fracture. Multivariate analysis using a multiple logistic model showed that medical facility category, age, type of treatment, and cause of fracture had statistically significant relations to mobility at the time of discharge. Of patients who could walk at the time of discharge, 83.7% (159/190) were alive two years after discharge. Multiple logistic model analysis identified gender as a significant contributing factor to this mortality. Among the survivors, 81.8% (130/159) retain the ability to walk. Logistic model analysis revealed that older age experience a significantly higher risk in losing mobility.