Secular increase and geographical differences in hip fracture incidence in Norway.

In 1988 and 1989, 2790 hip fractures were reported from the urban population of Oslo (annual incidence per 10,000 in the age group 50 years and older: women 118.7, men 45.4). For the same period, 385 fractures were reported from the rural population of the county Sogn og Fjordane (annual incidence per 10,000 in the age-group 50 years and older: women 74.6, men 36.7). The hip fracture incidence in Oslo had increased for all sex and age groups above 50 years (except women 50-59 years) in the 10-year period 1978/79 to 1988/89. The incidence of hip fractures in Sogn og Fjordane was only 65% of the incidence in Oslo. These results support previous reports on a secular increase and geographical differences in hip fracture incidence.