Table 5.

Significant clinical factors relating upper gastrointestinal bleeding in patients taking nonvitamin K oral anticoagulants.

Factor	Adjusted HR (95% CI)	p value
PPI	0 (0–2E + 134)∗	<0.001
Past digestive ulcer	29.114 (7.265–116.678)	<0.001

Analysis was done by Cox proportional hazard model with stepwise forward likelihood method. ^∗Adjusted HR of PPI presents 0 because no patients with upper gastrointestinal bleeding took PPI concomitantly. HR: hazard ration, CI: confidence interval, and PPI: proton pump inhibitor.