A National Hospital-Based Study of Hospitalized Patients With Primary Biliary Cholangitis

Epidemiological studies on primary biliary cholangitis (PBC) have been based primarily on tertiary referral case series. We aimed to estimate the incidence and prevalence and describe comorbidities in hospitalized patients with PBC in Italy using a national hospital-based data source. Data were extracted from the National Hospital Discharge Database, which includes all Italian individuals discharged from any hospital in the country. All adults diagnosed with biliary cirrhosis (International Classification of Diseases, Ninth Revision, Clinical Modification, 571.6) as the primary or secondary diagnosis from 2011 to 2015 were included. To determine whether a comorbidity was either more or less frequent in PBC patients compared with the general hospitalized Italian population, the standardized hospitalization ratio (SHR) was calculated. A total of 5,533 incident cases were identified from 2011 to 2015, 3,790 of whom were females (68.5%; female to male [F:M] ratio, 2.2:1). Prevalent cases were 9,664, of whom 7,209 were females (74.6%; F:M ratio, 2.9:1). The incident rate was 1.03 x 100,000 in males and 1.92 x 100,000 in females; prevalence was 1.89 x 100,000 in males and 4.75 x 100,000 in females. Extrahepatic autoimmune diseases, malignant neoplasms of liver and intrahepatic biliary ducts, and malignant neoplasms of gallbladder and extrahepatic bile ducts were found more frequently in PBC patients than in the general hospitalized population (SHR > 100), whereas cerebrovascular diseases and ischemic heart diseases were less frequent in PBC individuals (SHR < 100). Conclusion: This national study provides a survey of comorbidities associated with PBC. Hospitalized patients with PBC are more likely to have extrahepatic autoimmune diseases, hepatocellular carcinoma, and biliary tract cancers and a low risk of cardiovascular events.