Table 1.

CRISIS Sample Size Requirements under Various Assumptions about Time To Infection, Days at Risk, and Hazard Ratio

Median Time to Nosocomial Infection/Sepsis among Patients at Risk	Median Days Patients are at Risk for Outcome	Hazard for an Event in Placebo Arm, Relative to the Active Arm	Patients required for 80% Power	Patients required for 90% Power
6 days	3 days	1.5-fold	662	886
		2-fold	254	340
		2.5-fold	160	214
6 days	5 days	1.5-fold	476	636
		2-fold	180	240
		2.5-fold	112	150
6 days	7 days	1.5-fold	396	530
		2-fold	148	198
		2.5-fold	92	124
8 days	3 days	1.5-fold	820	1096
		2-fold	316	424
		2.5-fold	200	268
8 days	5 days	1.5-fold	570	762
		2-fold	218	290
		2.5-fold	136	182
8 days	7 days	1.5-fold	464	620
		2-fold	176	234
		2.5-fold	110	146
13 days	3 days	1.5-fold	1212	1622
		2-fold	474	634
		2.5-fold	302	404
13 days	5 days	1.5-fold	806	1078
		2-fold	312	416
		2.5-fold	196	264
13 days	7 days	1.5-fold	634	850
		2-fold	244	326
		2.5-fold	154	204