Table 3.

Hospitalizations for upper gastrointestinal (UGI) bleeding during warfarin treatment according to PPI co-therapy and concurrent use of specific antiplatelet drugs or NSAIDs. HR = adjusted hazard ratio, RD = adjusted rate difference per 10,000, CI = confidence interval. Both the HR and RD are adjusted for the study population (Medicaid or Medicare), demographic characteristics, warfarin indication and treatment duration, gastrointestinal disease, risk factors for warfarin-related bleeding, medications thought to affect bleeding risk, cardiovascular comorbidity, alcohol abuse, liver disease, and recent medical care utilization (Appendix Table 3 has detailed list of covariates).

	No PPI Co-therapy			PPI Co-therapy			HR (95% CI)	p-value	RD (95% CI)
	Person -years	UGI Bleeds	Rate/10,000	Person-years	UGI Bleeds	Rate/10,000
No concurrent antiplatelet drug or NSAID	46,240	449	97.1	12,269	134	109.2	0.86 ( 0.70 - 1.06 )	.1608	-13.5 ( -29.3 to 6.0 )
Any concurrent antiplatelet drug or NSAID	6,167	175	283.8	2,390	47	196.7	0.55 ( 0.39 - 0.77 )	.0004	-128.2 ( -172.4 to -66.4 )
Aspirin only	1,783	47	263.5	648	12	185.3	0.51 ( 0.27 - 0.97 )	.0388	-129.5 ( -193.0 to -9.0 )
NSAID only	2,346	71	302.7	745	15	201.2	0.56 ( 0.32 - 0.98 )	.0423	-134.1 ( -206.9 to -6.1 )
P2Y12/other antiplatelet only	1,626	42	258.4	749	13	173.5	0.54 ( 0.29 - 1.01 )	.0536	-119.0 ( -183.9 to 2.5 )
Multiple drugs	412	15	363.9	248	7	282.8	0.63 ( 0.25 - 1.54 )	.3089	-136.1 ( -271.5 to 197.6 )