Table 1.

Characteristics of the Derivation and Validation Cohorts

Characteristic	Derivation Cohort (n= 122)	Validation Cohort (n=109)	p-value
Age (years)	74.7 (6.3)	72.6 (7.1)	.02
Female sex n (%)	25 (20%)	29 (27%)	.27
Non-white n (%)	2 (2%)	6 (5%)	.11
Education
<High School	19 (17%)	18 (15%)	.52
High School	44 (36%)	32 (29%)
>High School	59 (49%)	58 (53%)
Unmarried n (%)	38 (32%)	46 (42%)	.12
Tobacco Exposure
None	29 (26%)	33 (31%)	.28
1-30 pack-years	48 (42%)	34 (32%)
>=30 pack years	36 (31%)	39 (38%)
Alcohol User	66 (58%)	58 (54%)	.53
Body mass index (kg/m²)	28.3 (5.6)	29.0 (5.6)	.36
Hypertension	99 (81%)	97 (90%)	.11
Hyperlipidemia	84 (70%)	90 (83%)	.02
Diabetes	56 (47%)	41 (38%)	.18
Stroke/Transient Ischemic Attack	26 (22%)	16 (15%)	.18
Cancer	9 (8%)	15 (14%)	.12
Geriatric Depression Scale	3.3 (3.0)	2.3 (2.1)	.005
Instrumental Activities of Daily Living <21	57 (49%)	54 (50%)	.90
Activities of Daily Living <18	10 (9%)	1 (1%)	.01
ASA Class^†
2	2 (2%)	0 (0%)	.33
3	21 (18%)	16 (15%)
4	97 (81%)	93 (85%)
Mini Mental State Examination	26.9 (2.6)	26.8 (2.7)	.74
Albumin (g/dL)
3.6-4.4	61 (64%)	75 (80%)	.02
≤3.5 or ≥4.5	34 (36%)	19 (20%)
Hematocrit (%)	37.0 (4.5)	36.2 (5.0)	.25
Abnormal Laboratory Values^*	24 (20%)	21 (19%)	.89
Urea nitrogen : creatinine ≥18	81 (69%)	67 (62%)	.30
Urgent Surgery	96 (79%)	75 (69%)	.09
Elective Surgery	26 (21%)	34 (31%)
Type of Surgery
CABG^‡	103 (84%)	77 (71%)	.01
Valve +/- CABG	19 (16%)	32 (29%)

Abnormal electrolytes values: sodium <135 or >154(mg/dL); glucose <60 or >200(mg/dL); white blood cell count <3.0 or >20 (×1000/mcL)

^†

ASA American Society of Anesthesiology

^‡

CABG-Coronary Artery Bypass Graft