2.3 | Procedures
The day of concomitant diagnosis of liver cirrhosis and diabetes was defined as the comorbid date. Persons who underwent insulin therapy for at least 28 days after the comorbid date were defined as insulin users, and those who never took insulin during the whole study period were defined as insulin nonusers. We defined the first date of insulin use as the index date. Variables considered as potential confounders in this study included age, sex, age at the diagnosis of diabetes, the duration of diabetes, antihypertensive and antidiabetic medications, statins, and aspirin. Comorbidities status before the index date included HCV (ICD-9-CM codes 070.41, 070.44, 070.51, 070.54, 070.70, 070.71, and V02.62) and HBV infections (ICD-9-CM codes 070.2, 070.3, and V02.61). We also calculated the Charlson comorbidity index (CCI) [15] and Diabetes Complication Severity Index (DCSI) scores [16] to assess the severity of diabetes.