The hip fracture incidence in the high-risk area Oslo continues to decline

Oslo in Norway has had the highest incidence of hip fractures in the world. The incidence in Oslo has been thoroughly described every decade since the late 1970s. The incidence in Oslo has previously been higher compared to the rest of Norway but has now decreased to a level below the country average.

The purpose of this study was to report the incidence of hip fractures in Oslo in 2019 and compare it with the incidence rates from the previous four decades.

Patients residing in Oslo in 2019 with a new hip fracture identified by searching the Oslo hospital's patient administrative systems and protocols from the operating theaters. The diagnosis was verified through medical records and/or radiographs. To compare with previous studies, the direct standardization method was used with the population of Oslo in 2019 as the standard.

A total of 758 hip fractures, 70% women, were identified in 2019. The age-standardized incidence rates per 10,000 person-years in 2019 (95% CI) were 45 (41.1-48.8) for women and 30 (25.8-33.8) for men. In women, there has been a continuous decline in age-standardized rates the last three decades and in men the last two decades. The most pronounced decline was seen in the oldest age groups over 70 years. There has been a secular decline in both cervical and trochanteric fractures; however, the decrease in trochanteric fractures was most distinct for males, with more than two times higher risk in 1996/1997 compared to 2019.

Incidence rates for hip fractures in Oslo in 2019 were the lowest rate reported since 1978. The decrease was significant for both men and women. For the first time, the incidence rates are below the national rates of Norway. However, the rates are still among the highest worldwide.