Table 2.

Clinical classification software categories used to identify comorbidities and associated diagnoses

CCS Category	Diagnosis
98 and 99	Hypertension
49 and 50	Diabetes mellitus
138	Esophageal disorders (excluding ICD-9-CM diagnoses f.or varices)
139	Gastroduodenal ulcer
140	Gastritis and/or duodenitis
141	Other disorders of stomach and duodenum
142	Appendicitis
143	Abdmoninal and groin hernia
144	Inflammatory bowel diseases
145	Intestinal obstruction
146	Diverticular disease
147	Anal and rectal conditions
148	Peritonitis and intestinal abscess
149	Benign biliary tract disease
152	Benign pancreatic disorders excluding diabetes mellitus
153	Gastrointestinal hemorrhage
154	Noninfectious gastroenteritis

CCS: Clinical classification software categories; ICD-9-CM: International classification of diseases, 9^th revision, clinical modification.