2.2 | Study design
T2DM was diagnosed based on ICD-9-CM code 250.xx with at least 2
outpatient claims within 1 year or one hospitalization. Persons with
ICD-9-CM code 571.5, 571.2, or 571.6 for at least 2 outpatient claims
within 1 year or one hospitalization were defined as having liver
cirrhosis. This method of defining T2DM and liver cirrhosis using
ICD-9-CM codes has been validated by studies; [12,13] the diagnostic
accuracy of diabetes and cirrhosis is 74.6% and 82.6%, respectively.
Persons with liver cirrhosis and esophageal varices with bleeding (456.0
and 456.2), ascites (789.59 and 789.5), hepatic encephalopathy (572.2),
or jaundice (782.4) were defined as having decompensated liver cirrhosis
[14] and were initially excluded from this study. Patients without
these cirrhotic complications were defined as having compensated liver
cirrhosis. We excluded persons who were diagnosed as having type 1
diabetes mellitus (ICD-9-CM code 250.1); who did not receive
antidiabetic medications; who were younger than 18 years or older than
80 years; who lacked gender information; who died or had renal failure,
stroke, ischemic heart disease, heart failure, HCC, esophageal varices
with bleeding, ascites, hepatic encephalopathy, jaundice, or hepatic
failure before the index date or within 6 months after the index date;
and who were diagnosed as having T2DM or cirrhosis during 1997–1999.