Identifying Patients With Hepatic Encephalopathy Using Administrative Data in the ICD-10 Era.

Hepatic encephalopathy (HE) is a common complication of cirrhosis resulting in relapsing-remitting mental status changes ranging from deficits in executive function to coma. Incident HE is associated with an abrupt increase in mortality1 and frequent hospitalization.2 To further the understanding of the burden and impact of HE at the population level, valid algorithms are required to identify patients in administrative data. An International Classification of Diseases (ICD)-9 code is specific for HE (572.2), offering a 0.92 positive predictive value (PPV) and 0.36 negative predictive value (NPV).3 When applied in an algorithm to patients with ICD-9 codes for cirrhosis (eg, 571.5), Kanwal et al4 found a PPV and NPV of 0.86 and 0.87. Unfortunately, the switch to ICD-10 in 2015 rendered algorithms validated using ICD-9 invalid. Kaplan et al5 previously showed that lactulose and rifaximin use correlated with grade of HE for Child classification. Herein, we validate a diagnostic coding algorithm for HE using ICD-10 and medication records.