The above calculation shows that the average NCB of warfarin therapy in recently diagnosed female afibbers, at or above the age of 75 years, is indeed slightly beneficial at 0.18%/year. It would appear to be detrimental for men at all ages, and for women below the age of 75 years. Of course, these numbers are average and whether or not warfarin therapy would be beneficial for an individual afibber would clearly depend on his or her age and CHADS2 score. Thus, warfarin therapy would likely be beneficial for an older woman (age 75 years or older) with a CHADS2 score of 3 or higher, but would almost certainly be detrimental for women with a CHADS2 score below 3 unless the reason for their CHADS2 score of 2 was a history of stroke or TIA. The same cut-off points would apply to men.
 Singer, DE, et al. The net clinical benefit of warfarin anticoagulation in atrial fibrillation. Annals of Internal Medicine, Vol. 151, September 1, 2009, pp. 297-305, pp. 355-56
 Olesen, JB, et al. Risks of thromboembolism and bleeding with thromboprophylaxis in patients with atrial fibrillation: a net clinical benefit analysis using a "real world" nationwide cohort study. Thrombosis and Haemostasis, Vol. 106, No. 4, October 2011, pp. 739-49