Table 2.

Univariate Logistic Regression Analysis by Study Period for Risk of Transfusion above a Defined Hgb Trigger

Variable	Period 1			Period 2			Period 3
	OR	CI	P value^a	OR	CI	p value^a	OR	CI	P value^a
Threshold > 8 gm/dL	1 (Reference)			0.52	0.34-0.79	0.003	0.37	0.24-0.59	<0.001
Threshold > 9 gm/dL	1 (Reference)			0.84	0.49-1.44	0.52	0.50	0.27-0.95	0.04
Threshold > 10 gm/dL	1 (Reference)			1.15	0.51-2.60	0.74	0.37	0.11-1.17	0.09^b

CI=95% Confidence Interval, OR=Odds Ratio

^a)

p values determined by univariate logistic regression analysis

^b)

Period 3 is significantly different than Period 2 by univariate analysis (OR: 0.32 [0.10-0.99], p=0.048)