Table 1.

Characteristics of Medicare Beneficiaries Undergoing Coronary Artery Bypass for 2006–2008

Preoperative Characteristics	Readmitted n=41,410 (16.9%)	Non-Readmitted n=203,464 (83.1%)	p-value
Mean Age (SD)	74.9 (6.1)	74.0 (5.8)	<0.001
Male (%)	66.2	68.7	<0.001
Non-white (%)	10.8	9.7	<0.001
Elective procedure (%)	43.6	49.8	<0.001
Low socioeconomic status (%)	26.1	24.5	<0.001
Comorbidities
Hypertension (%)	58.8	65.5	<0.001
Congestive heart failure (%)	17.6	12.9	<0.001
Valvular disease (%)	8.0	7.4	<0.001
Pulmonary circulation disorders (%)	1.7	1.4	<0.001
Peripheral vascular disease (%)	11.6	11.2	0.02
Chronic lung disease (%)	23.7	18.9	<0.001
Diabetes without complications (%)	24.8	26.2	<0.001
Diabetes with complications (%)	5.1	3.7	<0.001
Renal failure (%)	15.6	10.4	<0.001
Coagulopathy (%)	9.6	8.7	<0.001
Fluid and electrolyte disorders (%)	19.6	17.0	<0.001