PSC Clinical Epidemiology in China

Inclusion Criteria:

1. Retrospectively review PSC cases before April 1, 2002 will be identified by diagnosticcodes from the International Classification of Diseases (ICD)-9, and for those afterApril 1, 2002, we used ICD-10.
2. We identified patients using an electronic search of SuValue Research Database and HISof BFH-CMU and BYH-CMU using PSC related ICD codes (ICD-9: 576.1; ICD-10:K83.016/K83.016(China version)). To supplement the ICD search, an electronic keywordsearch for "primary sclerosing cholangitis" or "seclerosing cholangitis" was conductedon all radiology, endoscopy, pathology reports beginning on earliest date available inthe database of SuValue Research Database and HIS of BFH-CMU and BYH-CMU. We reviewedthe medical charts of identified patients and diagnostic criteria includingcholestatic biochemistry (ALP, GGT elevations), and typical imaging (MRCP or ERCP) orpathological features, excluding other known etiology. For patients with multiplevisits for PSC, we reviewed only the index visit. To ensure consistency, chart reviewwas independently assessed by two hepatologists. Discrepancies in compliance wereresolved by discussion between the two main reviewers. Any unresolved discrepancieswere decided by a third expert hepatologist.

Exclusion Criteria:

1. The cases with secondary sclerosing cholangitis caused by cholelithiasis, IgG4 relateddisease, malignancy or other known etiologies.
2. The cases with missing key results on clinical, biochemical (ALP, GGT, bilirubin),radiological (MRCP or ERCP) or histological investigations.