Secular trends in hip fracture incidence and recurrence.

UNLABELLED: The decline in hip fracture incidence is now accompanied by a further reduction in the likelihood of a recurrent hip fracture among survivors of the first fracture.
INTRODUCTION: Hip fracture incidence is declining in North America, but trends in hip fracture recurrence have not been described.
METHODS: All hip fracture events among Olmsted County, Minnesota residents in 1980-2006 were identified. Secular trends were assessed using Poisson regression, and predictors of recurrence were evaluated with Andersen-Gill time-to-fracture regression models.
RESULTS: Altogether, 2,752 hip fractures (median age, 83 years; 76% female) were observed, including 311 recurrences. Between 1980 and 2006, the incidence of a first-ever hip fracture declined by 1.37%/year for women (p < 0.001) and 0.06%/year for men (p = 0.917). Among 2,434 residents with a first-ever hip fracture, the cumulative incidence of a second hip fracture after 10 years was 11% in women and 6% in men with death treated as a competing risk. Age and calendar year of fracture were independently associated with hip fracture recurrence. Accounting for the reduction in first-ever hip fracture rates over time, hip fracture recurrence appeared to decline after 1997.
CONCLUSION: A recent reduction in hip fracture recurrence is somewhat greater than expected from the declining incidence of hip fractures generally. Additional research is needed to determine the extent to which this can be attributed to improved patient management.