Context: Current clinical guidelines recommend a drug holiday after extended use of oral bisphosphonates. However, no studies have investigated the impact of drug holidays before hip fractures on post-fracture mortality.
Objective: To investigate the effect of drug holiday on post-fracture mortality in patients with extended use of oral bisphosphonates.
Design: Retrospective population-based cohort study.
Setting: All patients with hip fractures in Victoria, Australia from 2014-18.
Patients: Patients adherent to oral alendronate or risedronate for ≥5 years prior to hip fracture.
Intervention(s): Group-based trajectory modelling categorized patients into different bisphosphonate usage after 5-year good adherence.
Main outcome measure(s): Post-fracture mortality.
Results: We identified 365 patients with good adherence (medication possession ratio ≥80%) to oral alendronate/risedronate for ≥5 years. Most patients (69%) continued to use oral bisphosphonates till admission for hip fracture; 17% had discontinued for one year and 14% had discontinued for two years. Post-fracture mortality was higher in patients who had discontinued risedronate for one year (Hazard ratio [HR] 2.37, 95% confidence interval [CI] 1.24-4.53) and two years (HR 3.08, 95% CI 1.48-6.41) prior to hip fracture. No increase or decrease in post-fracture mortality was observed in patients who had discontinued alendronate for one year (HR 0.59, 95% CI 0.29-1.18) or two years (HR 1.05, 95% CI 0.57-1.93) prior to hip fracture.
Conclusions: Post-fracture mortality is higher in people who discontinue risedronate, but not alendronate, for 1 or 2 years after being adherent to treatment for at least 5 years. The type of bisphosphonate may be a factor to consider when planning drug holidays.
Keywords: antiresorptive medication; bisphosphonate; hip fracture; osteoporosis.
© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.