. Author manuscript; available in PMC: 2015 Apr 1.

Published in final edited form as: Anesth Analg. 2014 Apr;118(4):809–817. doi: 10.1213/ANE.0000000000000028

Table 4.

Independent relationships among candidate predictors including BIS or ETAC group and the outcome of postoperative delirium, using non-iterative binary logistic regression.

Variable	Binary logistic regression
Variable	Odds ratio	95% CI	P value
BIS group	0.62	0.34 – 1.15	0.127
Average maintenance ETAC (aaMAC)	0.70 (per 0.1 aaMAC increase)	0.53 – 0.92	0.010
Units pRBCs	1.26 (per 1 unit)	1.10 – 1.43	0.001
ASAPS 4 (vs 1, 2, 3)	2.88	1.18 – 6.94	0.020
EuroSCORE	1.20 (per 1 point increase)	1.07 – 1.36	0.002
Norepinephrine dose (mcg/kg/min)	Not significant; point estimate 58, CI 0.026-1.3E5		0.301

Abbreviations: CI, confidence interval. BIS, Bispectral Index. ETAC, end-tidal anesthetic concentration. aaMAC, age-adjusted minimum alveolar concentration. pRBCs, packed red blood cells. ASA PS, American Society of Anesthesiologists Physical Status.