Covert, Minimal Hepatic Encephalopathy Highly Prevalent Worldwide

Covert, minimal hepatic encephalopathy (C/MHE), a complication of liver cirrhosis, is highly prevalent on a global scale, according to study findings published in The American Journal of Gastroenterology.

Researchers conducted a systematic review and meta-analysis using 101 eligible studies including 16,786 patients with liver cirrhosis across 25 countries. Per the Joanna Briggs Institute (JBI) Critical Appraisal Tool, 78 studies had low risk for bias, 20 had moderate risk for bias, and only 3 had high risk for bias.

Recommended tests to diagnose C/MHE include the psychometrics hepatic encephalopathy score (PHES), Scan test, Stroop test, inhibitory control test (ICT), critical flicker frequency (CFF) test, continuous reaction time (CRT) test, electroencephalogram, and evoked potential assessment, although PHES remains the gold standard for C/MHE diagnosis.

Using varying diagnostic methodology, the researchers calculated that the global prevalence of C/MHE was 40.9% (95% CI, 38.3-43.5%) among patients with liver cirrhosis. Similarly, the researchers calculated the global prevalence of C/MHE to be 39.9% in the studies that strictly used the PHES for diagnosis.

A range of factors influenced the heterogeneity of C/MHE prevalence, including geographic region, study sample size, sex ratio, higher mean age of study participants, and the Child-Pugh classification. According to geographic location, C/MHE was most prevalent in Africa at 58.8%, Southeast Asia at 48.4%, and the Eastern Mediterranean at 44.9%, while C/MHE prevalence was lowest in the Western Pacific at 36.5%, Europe at 37.2%, and the Americas at 38.2%.

Higher prevalence occurred in studies with sample sizes less than or equal to 200 participants. C/MHE prevalence increased as Child-Pugh classification scores became more severe (29.3%, 45.9%, and 61.6% for Child-Pugh A, B, and C classifications, respectively).

C/MHE prevalence increased among individuals with alcoholic liver cirrhosis (46.2%; 95% CI, 41.3%-51.1%) followed by viral hepatitis (40.8%; 95% CI, 36.7%-45.1%), nonalcoholic fatty liver disease (34.6%; 95% CI, 25.5%-45.0%), and — at the lowest prevalence — autoimmune liver disease (27.7%; 95% CI, 17.1%-41.5%).  

“The prevalence of C/MHE was 40.9% among patients with cirrhosis worldwide,” study authors noted.

Study limitations include using only traditional neuropsychological testing to obtain C/MHE diagnosis, lack of differentiation between covert and minimal hepatic encephalopathy, significant heterogeneity among prevalence estimates, potential for bias in results due to adoption of norms for diagnosing C/MHE from non-native populations, and inability to establish causality.

This article originally appeared on Gastroenterology Advisor