Background and Purpose— Clinical trials have illustrated warfarin’s protective effect on stroke risk in patients with atrial fibrillation (AF). The current study investigated temporal trends in AF prevalence, warfarin use, and its relation to stroke risk in Medicare patients with AF from 1992 to 2002. Methods— The Medicare 5% sample for 1992 to 2002 was used to create 1-year cohorts of patients with Medicare as primary payer throughout the year. International Classification of Diseases, Ninth Revision, Clinical Modification codes were used to identify AF, ischemic and hemorrhagic stroke, and comorbid conditions. A previously validated surrogate measure, prothrombin/international normalized ratio claims, was used to identify warfarin use. Cox proportional hazards regression was used to examine time to stroke with warfarin use as a time-dependent variable. Results— Among Medicare patients aged ≥65 years, AF prevalence increased from 3.2% in 1992 to 6.0% in 2002 with higher prevalence in older subsets of the study population. Among patients with AF, warfarin use increased significantly ( P ≤0.001) for each year examined, from 24.5% in 1992 to 56.3% in 2002. Stroke rates per 1000 patient-years declined from 46.7 in 1992 to 19.5 in 2002 for ischemic stroke but remained fairly steady for hemorrhagic stroke (range, 1.6 to 2.9). Time-to-event modeling confirmed a protective association of warfarin against ischemic stroke among Medicare patients with AF. Conclusions— This analysis represents an observational validation of stroke prevention in AF trials. The significant increase in warfarin use among patients with AF illustrates diffusion of trial evidence into clinical practice.

Background and Purpose-Dysphagia screening before oral intake (DS) is a stroke care quality indicator. The value of DS is unproven. Quality adherence and outcome data from the Paul Coverdell National Acute Stroke Registry were examined to establish value of DS. Methods-Adherence to the DS quality indicator was examined in patients with stroke discharged from Paul Coverdell National Acute Stroke Registry hospitals between March 1 and December 31, 2009. Patients were classified as unscreened (US), screened and passed (S/P), and screened and failed. Associations between screening status and pneumonia rate were assessed by logistic regression models after adjustment for selected variables. Results-A total of 18 017 patients with stroke discharged from 222 hospitals in 6 states were included. A total of 4509 (25%) were US; 8406 (47%) were S/P, and 5099 (28%) were screened and failed. Compared with US patients, screened patients were significantly more impaired. Pneumonia rates were: US 4.2%, S/P 2.0%, and screened and failed 6.8%. After adjustment for demographic and clinical features, US patients were at a higher risk of pneumonia (OR, 2.2; 95% CI, 1.7 to 2.7) compared with S/P patients. Conclusions-Data suggest that patients are selectively screened based on stroke severity. Pneumonia rate was higher in US patients compared with S/P patients. Clinical judgment regarding who should be screened is imperfect. S/P patients have a lower pneumonia rate indicating that DS adds accuracy in predicting pneumonia risk. The Joint Commission recently retired DS as a performance indicator for Primary Stroke Center certification. These results suggest the need to implement a DS performance measure for patients with acute stroke. (Stroke. 2010;41:2849-2854.)