Table 2.

Prevalence of the Most Frequent Readmission Diagnoses in the Training Data (2005–2008)

Readmission Diagnosis	ICD9 Code	Number of Patients	Percentage of Total Number of Patients (Total N = 92,530)
All-cause readmission	Any diagnosis	6629	7.16
General Symptoms (most common reasons 780.2 syncope and 780.6 fever)	780.xx	567	0.61
Symptoms involving respiratory system and other chest symptoms (most common reason 786.5 chest pain)	786.xx	526	0.57
Chronic ischemic heart disease	414.xx	364	0.39
Other symptoms involving abdomen and pelvis (most common 789.0 abdominal pain)	789.xx	243	0.26
Complications peculiar to certain specified procedures (most common 996.6 infection due to internal prosthetic device and 996.8 complication of transplanted organ)	996.xx	243	0.26
Heart failure	428.xx	233	0.25
Episodic mood disorders	296.xx	172	0.19
Depressive disorder not elsewhere classified	311.xx	142	0.15
Symptoms involving digestive system	787.xx	121	0.13
Gastrointestinal hemorrhage	578.xx	111	0.12
Pneumonia, organism unspecified	486.xx	101	0.11
Cardiac dysrhythmias	427.xx	81	0.09
Other acute and subacute forms of ischemic heart disease	411.xx	61	0.07