Bisphosphonate Use After Hip Fracture in Older Adults: A Nationwide Retrospective Cohort Study.

Objectives: The aim of this study was to investigate the association between bisphosphonate use and the risk of new fracture in a nationwide cohort of individuals with previous hip fractures, with emphasis on individuals above 80 years of age.

Design, Setting, And Participants: From a nationwide cohort with hip fracture (2006-2012) (n = 93, 601), each individual prescribed bisphosphonates after hip fracture (n = 5845) was matched with up to three individuals not prescribed bisphosphonates, resulting in a cohort of 21,363 individuals.

Main Outcome Measure: A new hip fracture.

Results: During a mean follow-up period of 2.98 (range, 0.02-8) years, 4581 fractures occurred in the cohort. Before the initiation of bisphosphonate therapy, individuals later prescribed bisphosphonates had an increased risk of hip fracture (multivariable adjusted odds ratio [OR], 2.63; 95% confidence interval [CI], 2.23-3.24) compared with controls. In the period after bisphosphonate therapy initiation, individuals prescribed bisphosphonates had a lower risk of hip fracture (multivariable adjusted hazard ratio [HR], 0.76; 95% CI, 0.65-0.90) compared with controls. Similar effects were seen after the initiation of bisphosphonates in individuals aged more than 80 years (HR, 0.79; 95% CI, 0.62-0.99). In contrast, the initiation of bisphosphonate therapy did not influence the risk of injurious falls not resulting in fracture (HR, 0.95; 95% CI, 0.86-1.05).

Conclusion: Bisphosphonate use was associated with a decreased risk of hip fracture in this nationwide cohort of older men and women, with similar risk reductions in individuals older than 80 years.