Warfarin Therapy and Risk of Hip Fracture Among Elderly Patients

Study Objective. To ascertain the relationship between warfarin therapy and subsequent hip fracture in a large elderly population. Design. Retrospective, population-based cohort study. Setting. Population-based health care administrative databases for Ontario, Canada. Patients. Elderly patients receiving warfarin (52,701 patients), thyroid replace-ment therapy (40,555), an oral corticosteroid (43,915), or a proton pump inhibitor (60,383). The proton pump inhibitor group served as controls. Measurements and Main Results. The association between warfarin therapy and subsequent hospitalization for hip fracture in elderly patients was examined by researching administrative data from January 1, 1994–March 31, 1999, for the elderly population of Ontario. Relative to patients receiving proton pump inhibitors, patients receiving warfarin (adjusted risk ratio [aRR] 0.94, 95 % confidence interval [CI] 0.81–1.09) or thyroid replacement therapy (aRR 1.02, 95 % CI 0.89–1.18) incurred similar risks o