Calculation of Risks of Bleeding and Stroke
Age Years
Select all applicable items.

Risk of Stroke per 100 Person Years
on warfarin not on warfarin
Risk of Major Bleeding on Warfarin
at 3 months       at one year

This tool applies only to patients with normal cardiac valves and ventricular function.
Consider the patient's diet and medication compliance when assessing bleeding risk.
For 5-year stroke risk <= 5%, aspirin is recommended unless the patient's 1-year bleeding risk is thought to be only 1%.
For 5-year stroke risk >= 6%, warfarin is recommended if the stroke risk exceeds the patient's likely 1-year major bleeding risk.

Beyth RJ, Quinn LM, Landefeld CS. Prospective evaluation of an index for predicting the risk of major bleeding in outpatients treated with warfarin. Am J Med 1998;105: 91-9.
Gage BF. Water,am AD. Sjammpm W. et al. Validation of clinical classification schemes for predicting stroke: results from teh national Registry of Atrial Fibrillation. JAMA 2001;285(22):2864-70.
Go AS, Hylek EM, Chang Y, et al. Anticoagulation therpay for stroke prevention in atrial fibrillation: how well do randomized trials translate into clinical practice? JAMA 2003:290(20):2685-92.
van Walraven C, et al. A clinical prediction rule to identify patients with atrial fibrillation and a low risk for stroke while taking aspirin. Arch Intern Med 2003;163:936-43.
Wang TJ, et al. A risk score for predicting stroke or death in individuals with new-onset atrial fibrillation in the community: the Framingham Heart Study. JAMA 2003;290:1049-56.