Table 1.

Sample Characteristics by Delirium Status

	Discovery Cohort		Replication Cohort
Matching Variables	Delirium	No Delirium	Delirium	No Delirium
Age (M, SD)	77.3 (5.0)	76.8 (4.7)	78.0 (4.4)	77.6 (4.2)
Female (%)	54	54	58	58
GCP (M, SD)	55.2 (5.6)	56.4 (5.6)	53.7 (5.0)	54.6 (5.1)
Type of surgery (%)
Orthopedic	92	92	83	83
Vascular	5	5	6	6
Gastrointestinal	3	3	11	11
Vascular comorbidity
Presence (%)	38	38	50	50
Total number (M, SD)	0.8 (1.0)	0.5 (0.8)	0.6 (0.8)	0.7 (0.8)
ApoE ɛ4 carrier (%)	13	13	28	28

Note: ApoE = Apolipoprotein E, a gene for which being an ApoE ɛ4 carrier has been associated with increased risk of Alzheimer’s Disease (19); GCP = General Cognitive Performance, a composite measure reflecting cognitive domains vulnerable to delirium (16); M = mean, SD = standard deviation. Vascular comorbidity: No differences between cases and controls for each of the six vascular comorbidities (myocardial infarction, congestive heart failure, peripheral vascular disease, cerebrovascular disease, hemiplegia, diabetes or diabetes with end organ damage) were observed in the pooled cohort.