Estimating the Burden of Nonalcoholic Steatohepatitis Using a Multistate Electronic Health Record Data Network (NASH)
PI(s): Jaideep Behari and Kathleen McTigue, University of Pittsburgh
Project Summary: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the United States, with an estimated prevalence of 24% in the general population and is commonly associated with the metabolic syndrome. Nonalcoholic steatohepatitis (NASH), the progressive form of NAFLD, is characterized by inflammation of the liver that can lead to fibrosis, cirrhosis, liver failure, and hepatocellular carcinoma. We examined electronic health record data from 11 million patients to quantify the occurrence of NASH with or without fibrosis and cirrhosis in patients with and without a diagnosis of NASH. This population-based sample included adult patients with International Classification of Diseases 10th and 9th Revision NASH diagnosis codes over two years merged into one cohort, and further stratified by fibrosis or cirrhosis codes. Patients without NASH diagnosis codes formed a comparison cohort. We excluded individuals with diagnostic or laboratory codes indicative of other liver diseases or pregnancy. Analysis suggests that NASH, and in particular NASH with advanced fibrosis, is underdiagnosed in adult patients of multiple United States health systems.
Two projects were completed on this subject. The second, “Limitations of Noninvasive Tests-based Population-level Risk Stratification Strategy for Nonalcoholic Fatty Liver Disease,” added PCORnet sites University of Florida (OneFlorida network) and Baylor University (REACHnet network).
Study Design: Observational study of electronic health records from the PaTH Network from eligible patients between July 1, 2017 to June 30, 2019.