Incidence and seasonal variation in hip fracture incidence among elderly women in Norway. The HUNT Study

In total, 782 women sustained a first hip fracture during follow-up, and the overall hip fracture incidence rate per 1000 person-years was 13.1 (95 % CI: 12.2-14.1). The hip fracture incidence increased exponentially by age from 2.1 (95% CI: 1.2-3.8) in the age group 65-69 years to 49.7 (95% CI: 41.2-59.8) among the women aged 90+, respectively. In age-stratified analyses no changes in the incidence of hip fractures were observed during the nine years of follow up. The occurrence of fractures varied by season of the year, characterized by higher fracture rates during the winter months. In conclusion, the hip fracture rates in this population of elderly women are highest in the winter months. There was, however, no indication of an increasing hip fracture incidence in this rural area. Compared to similar studies from more urban areas in Norway, the hip fracture rates in this population seem somewhat lower.