“…To examine the clinical characteristics of the study population, we extracted demographic variables, diagnostic and surgical procedure codes, socioeconomic information (including monthly income and urbanization level [4 levels, 1=urban and 4=rural]), number of outpatient visits in the past year, Charlson Comorbidity Index,19 revised cardiac risk index (including 6 variables: high‐risk surgery, cerebrovascular disease, ischemic heart disease, congestive heart failure, DM, and renal insufficiency),20, 21 and adapted Diabetes Complications Severity Index for the severity of DM 22, 23, 24. We also identified other comorbidities related to general health and treatment with concomitant medications, including antidiabetic drugs, alpha‐blockers, angiotensin‐converting‐enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, diuretics, other antihypertensive drugs, aspirin, clopidogrel, ticlopidine, warfarin, dipyridamole, nitrates, and statins.…”