Are family physicians using the CHADS2 score
Objective To assess whether family physicians are using the CHADS2 (congestive heart failure, hypertension, age ≥ 75, diabetes mellitus, and stroke or transient ischemic attack) score in the decision to initiate warfarin therapy to prevent stroke in patients with atrial fibrillation.

Design Retrospective analysis of the medical records of patients with atrial fibrillation.

Setting Data were gathered from records at 3 clinics in a primary care network in Edmonton, Alta.

Participants The medical records of patients with atrial fibrillation who were currently taking warfarin therapy.

Main outcome measures Percentage of patients whose CHADS2 scores indicated warfarin therapy for stroke prophylaxis compared with the actual percentage of patients taking warfarin therapy. Data on patients’ age, number of medications, and number of comorbid conditions were also recorded.

Results Among these patients, 7% had a CHADS2 score of 0, for which no warfarin therapy was indicated; 21% had a score of 1, for which either acetylsalicylic acid or warfarin was indicated; and 72% had a score of 2 or greater, for which warfarin therapy was indicated. About 80% of patients were taking medication to control their heart rate.

Conclusion The CHADS2 score is not being used in all cases to assess the need for warfarin therapy for preventing stroke in patients with atrial fibrillation. The CHADS2 score might be of limited use because it is not sensitive enough to stratify patients clearly into high-, intermediate-, and low-risk groups. Although guidelines for stroke prevention should be followed, the CHADS2 portion of the guidelines might not be the most effective way to assess patients’ risk of stroke.