We agree that in trials of warfarin for atrial fibrillation, elderly patients at high risk for falls were excluded, and thus there is relatively little evidence on which to base decision making for these patients. In our retrospective cohort, the adjusted odds ratio of osteoporotic fractures was 1.25 in Medicare beneficiaries prescribed long-term warfarin therapy, representing a 25% increase in relative risk. In our prospective cohort, the increase in relative risk was slightly larger (32%).
Gage BF, Birman-Deych E, Radford MJ. The Association of Warfarin Use With Osteoporotic Fracture in Elderly Patients With Atrial Fibrillation—Reply. Arch Intern Med. 2006;166(14):1525. doi:10.1001/archinte.166.14.1525-b