Table 1.

ICD-9-CM Codes for Study Populations

	Number of Patients	Hospitals	ICD-9-CM Codes	Disease Staging
Coronary artery bypass grafting	84,656	123	36.10–36.39
Coronary angioplasty	149,375	162	36.01, 36.02, 36.05, 36.06
Carotid endarterectomy	35,374	311	38.12
Abdominal aortic aneurysm repair	8855	301	38.34, 38.44, 38.64	CVS-01
Total hip replacement	74,663	360	81.51, 81.52
Acute myocardial infarction			410.0, 410.01, 410.1, 410.11
			410.2, 410.21, 410.3, 410.31
			410.4, 410.41, 410.5, 410.51
			410.6, 410.61, 410.7, 410.71
	170,831	378	410.8, 410.81, 410.9, 410.91
Stroke			433.01, 433.11, 433.21, 433.31
			433.81, 433.91, 434.01, 434.11,
	125,112	389	434.91, 436