Abstract WP246: Long Term Risk of Hip Fracture After Ischemic Stroke

Abstract

Introduction: The recent Insulin Resistance Intervention after Stroke trial found that pioglitazone decreased the risk of stroke and myocardial infarction in patients with insulin resistance and a recent cerebrovascular event. However, by 5 years, patients receiving pioglitazone had a significantly increased risk of bone fracture requiring surgery or hospitalization compared to patients who received placebo (5.1% versus 3.2%). Data is lacking on the long-term real-world risk of bone fracture among patients with ischemic stroke. Methods: We performed a retrospective cohort study using inpatient and outpatient claims data between 2008-2015 from a nationally representative 5% sample of Medicare beneficiaries. We included patients who were ≥65 years old and hospitalized with ischemic stroke, defined by validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. We excluded patients who had a prior or concurrent hip fracture diagnosis at the time of ischemic stroke. The primary outcome was hip fracture requiring hospitalization. Survival statistics were used to calculate incidence rates and Kaplan-Meier statistics were used to calculate cumulative rates of hip fracture. Results: Among the 1,952,305 beneficiaries in our sample, 60,099 patients developed an ischemic stroke in the absence of a prior or concomitant hip fracture. During 4.5 (±2.2) years of follow-up, the incidence of hip fracture was 1.6 (95% CI, 1.5-1.6) per 100 person-years in the patients with ischemic stroke versus 0.6 (95% CI, 0.6-0.6) per 100 person-years in patients without ischemic stroke. The cumulative 5-year rate of hip fracture was 7.6% (95% CI, 7.2-8.0%) among patients with ischemic stroke compared to 2.8% (95% CI, 2.8-2.9%) among the remaining Medicare beneficiaries. Conclusions: We found that the 5-year cumulative risk of hip fracture in the overall population of Medicare beneficiaries with ischemic stroke was approximately 7.5%.