. Author manuscript; available in PMC: 2009 Feb 15.

Published in final edited form as: JPEN J Parenter Enteral Nutr. 2004;28(2):79–84. doi: 10.1177/014860710402800279

Table IV.

Regression analysis of predictors of pepsin concentration (μg/mL) in tracheal secretions at 2-hour (N = 160) data collection point

Step	Variable entered	R²	R²_Change	Final model coefficients
Step	Variable entered	R²	R²_Change	Unstandardized (SE)	Stabdardized (β)
1	Pepsin concentration in gastric secretions (μg/mL)	.36^***	.359^***	0.28 (0.03)^***	0.57^***
2	Visible blood in secretions (0 = no, 1 = yes)	.39^***	.027^**	−36.4 (14.3)^*	−0.16^*
3	Volume of tracheal secretions (mL)	.39^***	.002	−20.9 (28.2)	−0.05
	R²_{Adj(final model)} = .38			58.1 (15.4)	—
				Constant

p < .05;

^**

p < .01;

^***

p < .001.