Here - American Geriatrics Society

P OSTER
A BSTRACTS
of all strokes in the elderly. Warfarin anticoagulant therapy reduces
annual ischemic stroke risk by about two thirds in AF patients. With
institution of coverage for medications by Medicare Part D program
introduced in 2006, we wanted to know whether rates of warfarin use
were higher than previously reported after institution of the program.We
also used the Medicare Part D prescription drug data to examine
national warfarin use by patient characteristics and geographic
location.
Methods: We conducted a retrospective cohort study of 41,447
Medicare beneficiaries aged 66 and older with at least 2 atrial fibrillation
diagnoses in 2008 and at least 1 in 2008. All subjects were enrolled
in Medicare Part D by 2008. Chi-square test was used to examine
differences in warfarin use (defined as 2 warfarin prescriptions in
2008) by patient characteristics (age, ethnicity, sex, Medicaid eligibility,
entering Part D coverage gap, comorbidities, having contraindications
to warfarin, and seeing a cardiologist or a PCP) and by Hospital
Referral Regions. Hierarchical generalized linear models were used
to examine how patient characteristics impact the likelihood of warfarin
use only among patients with no warfarin contraindications, a
sample size of 34,947.
Results: The overall use rate was 66.8%. In bivariate analysis,
patients who received warfarin therapy were more likely [P