Atrial fibrillation is commonly associated with stroke.  Use of the CHA2DS2-VASc model provides a good risk stratification strategy that can help determine who to anticoagulate and who not to anticoagulate in non-valvular afib.  Oral anticoagulation must be balanced against bleeding risk and coupled with shared decision-making.  The CHA2DS2-VASc model can be deciphered as followed, one point for each risk factor except two points where so indicated:  C stands for history of congestive heart failure, H for hypertension, A for age 75 or older (two points), D for diabetes, S for previous stroke or TIA, V for vascular disease (MI, PTCA/CABG, angiographic CAD, PVD, etc), A for the second age range in 65-74 (in both men and women), and the Sc stands for female sex, which scores one point and is becoming controversial.  Some European societies are going away from the Sc component and back to CHA2DS2-VA.  Chronic oral anticoagulation should be strongly considered for men with a score of 2 or greater, and women with a score of 3 or greater.  Thus a 75-year-old man with a history of CHF and HTN would score a 4, and a woman age 80 with diabetes, chf, and vascular disease and previous stroke would score an 8 (if we count the now controversial female sex).  Both would then be considered prime candidates for oral anticoagulation, without relative or absolute contraindications, and with proper informed consent.