Epidemiology of PrImary Biliary Cholangitis in Spain

Primary biliary cholangitis (PBC) is a rare, long-term liver disease that can slowly damage the bile ducts, eventually leading to cirrhosis and, in some cases, the need for a liver transplant. The goal of this non-interventional, multi-database study is to characterize the epidemiology of PBC in Spain by estimating its prevalence (cross-sectional study) and incidence (cohort study).The main question it aims to answer is:

* What is the prevalence of PBC in Spain on a specific index date (31 December 2025)? * What is the annual incidence of newly diagnosed PBC in Spain? * How many patients with PBC receive first-line and second-line therapies in routine clinical practice? * What proportion of patients with PBC develop cirrhosis and/or require liver transplantation, and how long does it take for these events to occur after diagnosis? * Which factors are associated with poorer outcomes in patients with PBC?

Researchers will use anonymised information from several large Spanish databases (BIFAP, SIDIAP, the Andalusian PBC Registry and the Spain RDR-Galicia registry) to identify adults with and without PBC and follow them over time.

No patients will be contacted directly or asked to attend any study visits, and no additional tests or treatments will be carried out. All information will come from routinely collected healthcare data on adults with a diagnosis of PBC, which will be fully anonymised before analysis.