Qureshi and colleagues mentioned that they observed a 72% increase in the risk of gastrointestinal bleeding in hemodialysis patients with atrial fibrillation (AF) who were on warfarin compared with those not on warfarin and questioned the only 44% increase in the risk of bleeding in dialysis patients with AF who were on warfarin compared with those not on warfarin in our study. 1,2 Contrary to only gastrointestinal bleeding in the study by Khalid et al, 1 the "bleeding" definition in our study

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... ncluded intracerebral bleeding, gastrointestinal bleeding, intraocular bleeding, hematuria, and unspecified location of bleeding, which could be a possible reason for the difference in bleeding risk between the 2 studies. 1,2 Similar to Khalid et al, 1 Winkelmayer and colleagues 3 studied the association between warfarin use and the risk of gastrointestinal bleeding in hemodialysis patients with AF and found no association. Qureshi and colleagues also mentioned that they observed a 78% reduction in the risk of mortality in hemodialysis patients with AF who were on warfarin compared with those not on warfarin and mentioned that mortality risk assessment could be important when considering risk-benefit assessment on warfarin use in AF patients undergoing dialysis. 1 Chan and colleagues 4 also conducted a similar study and found that warfarin use was associated with a 27% higher risk of mortality in hemodialysis patients. In our AF cohort, we had access to information on patients' mortality (all-cause mortality). 5 In our study, we wanted to determine the association between warfarin use and the risk for stroke and bleeding (pharmacological actions) in AF patients undergoing dialysis. 2 Moreover, AF patients undergoing dialysis are most often very sick (as a result of multiple comorbidities) or terminally ill. 2 In these dialysis patients, the outcome of all-cause mortality may or may not be related to stroke or bleeding outcome (although such dialysis patients might have died during the hospital admission or emergency room visit for stroke or bleeding outcome). Therefore, we did not determine the association between warfarin use and all-cause mortality in AF patients undergoing dialysis.