Prevalence and quality of warfarin use for patients with atrial fibrillation in the long-term care setting.

BACKGROUND: Evidence-based clinical practice guidelines recommend the use of warfarin sodium for stroke prevention in most patients with atrial fibrillation (AF) who do not have risk factors for hemorrhagic complications, irrespective of age.
METHODS: The medical records of all residents of a convenience sample of long-term care facilities in Connecticut (n = 21) were reviewed. The percentages of all patients with AF (AF patients) and ideal candidates for warfarin therapy (ie, AF patients with no risk factors for hemorrhage) who received warfarin were determined; for patients receiving warfarin, the percentage of days spent in the therapeutic range of international normalized ratio (INR) values (2.0-3.0) was also assessed. The relationship between receipt of warfarin and the presence of stroke and bleeding risk factors was assessed in multivariate models.
RESULTS: Atrial fibrillation was present in 429 (17%) of the 2587 long-term care residents. Overall, 42% of AF patients were receiving warfarin. However, only 44 (53%) of 83 ideal candidates were receiving this therapy. In residents who received warfarin therapy, the therapeutic range of INR values was maintained only 51% of the time. The odds of receiving warfarin in the study sample decreased with increasing number of risk factors for bleeding and increased (nonsignificant trend) with increasing number of stroke risk factors present.
CONCLUSIONS: Atrial fibrillation is very common among residents of long-term care facilities. Even among apparently ideal candidates, warfarin therapy is underused for stroke prevention in patients with AF. Prescribing decisions and monitoring related to warfarin therapy in the long-term care setting warrant improvement.