Validation of the Korean Stroop Test in Diagnosis of Minimal Hepatic Encephalopathy

The burden of minimal hepatic encephalopathy (MHE) is significant, but no universal criteria for diagnosis have been established. We aimed to validate the Korean Stroop Test for MHE screening. Chronic hepatitis B-related liver cirrhosis patients were recruited prospectively from 13 centers. The Korean Stroop Test consisted of two Stroop-off states (color and word) and two Stroop-on states (inhibition and switching). Accuracy adjusted psychomotor speed (rate correct score) of these tests were analyzed. Sex- and age- adjusted rate correct scores of these tests were rated as the Korean Stroop Score (K-Stroop score). MHE was diagnosed when Portosystemic Encephalopathy Syndrome Test (PHES) scores were below -4. A total of 220 liver cirrhosis patients and 376 healthy controls were enrolled. Prevalence of MHE was 20.6% in cirrhosis patients. Rate correct scores and the K-Stroop score showed significant differences between healthy controls, cirrhosis patients without MHE, and cirrhosis patients with MHE. The rate correct score of the K-Stroop score was 0.74 (95% Confidence Interval: 0.66-0.83, P < 0.001). Female gender and the K-Stroop score were significant for MHE diagnosis. The Korean Stroop Test is simple and valid for screening of MHE.