Table 2.

Hospitalizations for bleeding during warfarin treatment according to site of the bleeding and PPI co-therapy. 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	Former PPI Co-therapy	PPI Co-therapy
Person-years	52,407	8,654	14,658
Upper gastrointestinal
Bleeding hospitalizations	624	159	181
Rate/10,000 person-years	119.1	183.7	123.5
HR (95% CI)		1.00 ( 0.82- 1.21)	0.76 ( 0.63- 0.91)
RD (95% CI)		-0.3 ( -21.0 to 24.7)	-28.7 ( -44.0 to -10.3)
p-value		0.9799	0.0035
Other gastrointestinal
Bleeding hospitalizations	936	280	403
Rate/10,000 person-years	178.6	323.5	274.9
HR (95% CI)	1	1.10 ( 0.95- 1.27)	1.07 ( 0.94- 1.22)
RD (95% CI)		17.1 ( -9.5 to 47.9)	13.1 ( -10.6 to 40.1)
p-value		0.2195	0.2927
Other major bleeds
Bleeding hospitalizations	801	205	259
Rate/10,000 person-years	152.8	236.9	176.7
HR (95% CI)		1.13 ( 0.95- 1.33)	0.98 ( 0.84- 1.15)
RD (95% CI)		19.1 ( -7.4 to 50.4)	-3.0 ( -24.8 to 22.4)
p-value		0.1676	0.8014