TABLE 3.

The association between the severity of postoperative delirium and the preoperative homocysteine, postoperative C-reactive protein, or their interaction.

	β Coefficient (95% CI)	P-value	β Coefficient (95% CI)	P-value	β Coefficient (95% CI)	P-value
	Univariate		Main effect		Interaction effect
Postoperative delirium severity before adjustment
Postoperative CRP	0.46 (0.15, 0.77)	0.004	0.45 (0.14, 0.76)	0.005	0.43 (0.12, 0.75)	0.007
Preoperative homocysteine	0.15 (−0.16, 0.47)	0.344	0.10 (−0.21, 0.40)	0.544	0.07 (−0.24, 0.39)	0.654
Interaction of CRP and Homocysteine	N.A.		N.A		0.10 (−0.17, 0.37)	0.466
Postoperative delirium severity after adjustment for age, preoperative MMSE, sex, and day of postoperative CRP measurement
Postoperative CRP	0.47 (0.18, 0.76)	0.002	0.47 (0.17, 0.76)	0.002	0.45 (0.16, 0.75)	0.003
Preoperative homocysteine	0.10 (−0.22, 0.41)	0.546	0.03 (−0.28, 0.34)	0.832	0.00 (−0.32, 0.32)	0.981
Interaction of CRP and Homocysteine	N.A.		N.A.		0.09 (−0.17, 0.36)	0.476

β, beta; CI, confidence interval; CRP, C-Reactive Protein; MMSE, Mini-Mental State Exam; N.A., Not applicable. The variables were scaled with Z scores in the models. Linear regression was used to analyze the data, assuming a β Coefficient of 0 under the null hypothesis.