Background: The prevalence of atrial fibrillation (AF) increases dramatically with advancing patient age, and, as a result, this condition is common in persons residing in the long-term care setting.
Objectives: To assess the knowledge and attitudes of physicians regarding the use of warfarin for stroke prevention in patients with atrial fibrillation in long-term care facilities.
Methods: We surveyed physicians actively providing primary care to older patients in 30 long-term care facilities located in New England, Quebec, and Ontario. Physicians were requested to complete a structured questionnaire about use of warfarin therapy for stroke prevention in patients with AF residing in long-term care facilities. The questionnaire included two clinical scenarios designed to provide substantial contrasts in patient characteristics including underlying comorbidity, functional status, bleeding risk, and stroke risk.
Results: A total of 269 physicians were asked to participate in the survey, and 182 (67.7%) completed the questionnaire between February 1, 1995, and July 31, 1995. Only 47% of respondents indicated that the benefits of warfarin therapy "greatly outweigh the risks" in this setting; the remainder of physicians indicated that benefits only "slightly outweigh the risks" (34%) or that risks "outweigh benefits" (19%). The most frequently cited contraindications to warfarin use were: excessive risk of falls (71%), history of gastrointestinal bleeding (71%), history of other non-central nervous system bleeding (36%), and history of cerebrovascular hemorrhage (25%). Among the 164 physicians who reported using the international normalized ratio to monitor warfarin therapy, 27% indicated a target range with a lower limit less than 2, 71% indicated a target range between 2 and 3, and 2% indicated an upper limit greater than 3. Among respondents who answered questions about the two clinical scenarios, estimates of the risk of a stroke without warfarin therapy and the risk of an intracranial hemorrhage with therapy varied widely.
Conclusions: Our findings suggest that many uncertainties surround the decision to prescribe warfarin to patients with AF in the long-term care setting, as well as questions about the appropriate intensity of this treatment when it is prescribed. Concerns about the risks of bleeding appear to prevail over stroke prevention when physicians make such prescribing decisions.