Table 1.

Specific ICD-9 diagnostic codes used to categorize readmission causes into groups of system-based criteria.

Failure to thrive	V5789	Rehabilitation procedure nec	DVT/PE	4538	Venous thrombosis nec	Distal embolization	44422	Lower extremity embolism
	V5873	Aftercare following surgery/circulatory system-nec		41519	Other pulmonary embolism, infarct	Device/Aneurysm-related	4414	Abdominal aortic aneurysm
	V571	Physical therapy nec	Pulmonary	486	Pneumonia-organism NOS		99674	Complication other vascular device/graft
	V5849	Other postoperative aftercare		51881	Respiratory failure		99662	React- other vascular device/graft
	2765	Hypovolemia		49121	Obstructive chronic bronchitis with active exacerbation		9972	Surgical complication peri vascular system
	27651	Dehydration		5070	Food/vomit pneumonitis
Cardiac	4280	Congestive heart failure		5185	Post traumatic pulmonary insufficiency
	41401	Coronary atherosclerosis native vessel		9972	Surgical complication: respiratory system
	41071	Subendothelial infarct: initial	GI	9974	Surgical complication: GI tract
	42731	Atrial fibrillation		5770	Acute pancreatitis
	78659	Chest pain nec		00845	Clostridium difficile infection
	42781	Sinoatrial node dysfunction	SBO	56081	Intestinal adhesion with obstruction
	78650	Chest pain NOS		5609	Intestinal obstruction NOS
Infection	99859	Other postoperative infection	Renal	5849	Acute renal failure NOS
	0389	Septicemia NOS	CVA	43491	Cerebral arterial occlusion NOS with infarction
	5990	Urinary tract infection NOS	Wound	55321	Incisional hernia
	03811	Staph aureus septicemia		99813	Seroma procedure culture
				99831	Disruption of internal operative wound