Table 1. Baseline patient characteristics by level of renal functiona

CharacteristicGFR ≥ 60 (n = 13,292)GFR 30 to 59 (n = 4118)GFR < 30 (n = 424)Dialysis (n = 383)
a GFR estimated glomerular filtration rate in cc/min/1.73 m2; COPD chronic obstructive pulmonary disease; CHF congestive heart failure during the month prior to surgery, TIA history of transient ischemic attack; DNR do not resuscitate.
b P ≤ 0.05; c P ≤ 0.1; d P ≤ 0.001. P values are for pair-wise χ2 tests (patients with a GFR ≥ 60 cc/min per 1.73 m2 used as reference category for each comparison). P ≤ 0.002 for overall χ2 tests across all groups for all variables where pair-wise tests show a statistically significant difference between the reference category and one or more groups.
Age > 65 yr44%70%d71%d55%d
Male99%99%97%d99%
White79%84%d85%d57%d
Diabetic patients31%42%d56%d61%d
Diabetic patients on insulin16%25%d39%d47%d
COPD19%21%b22%b14%c
History of CHF3%7%d13%d10%d
History of TIA4%7%d6%4%
History of stroke9%12%d13%c13%b
Dyspneic at rest1%2%5%d2%
Current smokers63%43%d38%d27%d
Alcohol users16%8%d7%d2%d
Weight loss3%3%4%6%d
DNR order0.7%1.0%b1.7%b2.6%d