Table 1.

ICD-9-CM comorbidity codes included in this study

ICD-9-CM codes	Code description
250.00–250.93	Diabetes mellitus
278.00, 278.01, v85.3, v85.4	Morbid obesity, obesity not otherwise specified
412	Prior myocardial infarction (MI)
414.00, 414.01, 414.06	Coronary artery disease (CAD)
428.0	Congestive heart failure
440.1, 440.20–440.24, 440.29, 440.30–440.32, 440.4, 440.8, 440.9, 441.00–441.03, 441.3–441.7, 441.9, 442.3, 442.82–442.84, 442.89, 443.0, 443.1, 443.2–443.24, 443.29, 443.81, 443.82, 443.89, 443.9, 440.0, 444.1, 444.21, 444.22, 444.81, 444.89, 445.01, 445.02, 445.81	Peripheral arterial disease
v12.51	History of thromboembolism
490, 491.0, 491.1, 491.20–491.9, 492.0–492.8, 493.00–493.92, 494.0, 494.1, 495.0–495.9, 496	Chronic lung disease

ICD-9-CM = International Classification of Diseases, 9^th Revision, Clinical Modification.