Table 2.

Sample size with respect to clinically important bleeding outcome

		True underlying relative risk (PPI vs placebo)
		0.7	0.6	0.5
Event rate in placebo group	3%	47.1%	74.6%	92.6%
	4%	60.1%	86.6%	97.8%
	5%	70.7%	93.4%	99.4%
	6%	79.1%	96.9%	99.9%

This table highlights consideration for clinically important gastrointestinal (GI) bleeding. It presents combinations of relative risk reductions ranging from 30% to 50%, and baseline risks between 3% and 6% for which we will achieve 85% power. With a baseline risk of 3% and a relative risk reduction of 50%, the absolute benefit of will be a 1.5% difference. Other highlighted cells correspond to absolute risk reduction of greater than 1.5%. In summary, across the range of plausible baseline risks in the shaded boxes, 4800 patients will provide at least 85% power to detect effects of pantoprazole as large as, or greater than, this small important reduction in clinically important GI bleeding. This sample size reflects feasible enrolment in an acceptable 4-year time frame, accounting for any non-compliance or loss to follow-up, in the context of hybrid serial funding for Re-Evaluating the Inhibition of Stress Erosions.

PPI, proton pump inhibitor.