Table 1.

Baseline Characteristics of the Derivation and Validation Cohorts, American College of Surgeons National Surgical Quality Improvement Program, 2005–2008

	Derivation Cohort (Years 2005–2007)		Validation Cohort (Year 2008)
	Frequency	Percent	Frequency	Percent
Sexc
Female	130,407	56.32	100,305	57.02
Male	101,126	43.67	75,617	42.98
Race
White, Not of Hispanic Origin	166,219	71.79	129,870	73.82
Black, Not of Hispanic Origin	23,350	10.08	17,954	10.21
Hispanic	16,123	6.96	10,708	6.09
Asian or Pacific Islander	4,264	1.84	3,591	2.04
Other/Unknown	21,592	9.33	13,802	7.85
Age, (years)*
16 – 39	41,836	18.07	29,542	16.79
40 – 49	36,617	15.81	26,671	15.16
50 – 59	46,565	20.11	35,431	20.14
60 – 69	45,218	19.53	36,056	20.5
70 – 79	38,654	16.69	29,621	16.84
≥80	22,656	9.78	18,604	10.57
ASA Classification*
1	15,768	6.81	10,796	6.14
2	92,072	39.76	68,624	39.01
3	103,929	44.88	80,202	45.59
4	19,098	8.25	15,654	8.9
5	529	0.23	407	0.23
General Anesthesia*
No	9,221	3.98	8,532	4.85
Yes	222,315	96.01	167,376	95.14
Surgery Type
General Surgery	182,625	78.87	122,734	69.76
Vascular	38,495	16.63	27,587	15.68
Other	10,428	4.5	25,604	14.55
Emergency case
No	191,751	82.81	146,966	83.54
Yes	39,797	17.19	28,959	16.46
Transfer Status
Acute Care Hospital	6,218	2.69	4,109	2.34
Admitted directly from home	221,078	95.48	168,309	95.67
Chronic Care Facility	3,386	1.46	2,878	1.64
Other	866	0.37	629	0.36
Dyspnea
No	199,299	99.86	152,484	99.87
Yes	32,249	13.92	23,441	13.32
>10% loss body weight in last 6 months
No	222,928	96.28	170,415	96.87
Yes	8,620	3.72	5,510	3.13
Systemic Inflammatory Response Syndrome, Sepsis, Severe Sepsis or Septic Shock
No	202,699	87.54	156,362	88.88
Yes	28,849	12.46	19,563	11.12
Modified Charlson Comorbidity Index
0	150,258	64.89	115,654	65.74
1	43,594	18.83	34,795	19.78
2–3	25,182	10.88	17,477	9.93
4–5	4,853	2.1	2,993	1.7
≥6	7,661	3.31	5,006	2.85
Total operation time, (minutes)*
0 – 119	125,778	54.32	97,058	55.17
120 – <299	90,773	39.2	67,617	38.44
300 – 359	6,825	2.95	5,167	2.94
≥360	8,153	3.52	6,047	3.44

^cTotals within variables may vary due to missing data.