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Seattle-Denver Center of Innovation (COIN)


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COIN Affiliate Investigators

COIN Affiliate Investigator


George N. Ioannou, MD, MS
Title: Professor, Gastroenterology, University of Washington
Director, VA Puget Sound Health Care System Hepatology
Location: Seattle
University of Washington webpage
See Dr. Ioannou's Dimensions profile that includes: publications, grants, datasets, patents and clinical trials
Dr. Ioannou is an Investigator with HSR&D, Director of Hepatology at VA Puget Sound health Care System and a Professor of Medicine at the University of Washington. He received his MD from Oxford University and his MS from the School of Public health, Division of Epidemiology at the University of Washington. His research interests include the epidemiology and outcomes of chronic liver disease, cirrhosis, hepatocellular carcinoma, NAFLD, optimizing outcomes in liver transplantation, antiviral treatment for hepatitis C virus and predictive modeling. He currently serves as PI of a VA HSR&D IIR focused on developing and implementing tools for predictive outcomes of surgery in patients with cirrhosis. He also serves as co-PI of the HSR&D funded COVID-19 Observational Research Collaboratory (CORC).
Dr. Ioannou also receives funding from the NCI (grants on Liver Cancer Disparities and Effectiveness of Liver Cancer Screening) and NIDDK (Development of a novel, portable self-administered device that measures critical flicker frequency as a test for minimal hepatic encephalopathy).

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Recent Publications




Vutien P, Li R, Karkar R, Munson SA, Fogarty J, Walter K, Yacoub M, Ioannou GN. Evaluating a Novel, Portable, Self-Administrable Device ("Beacon") that Measures Critical Flicker Frequency as a Test for Hepatic Encephalopathy. Am J Gastroenterol. 2023 Feb 3. doi: 10.14309/ajg.0000000000002211. Epub ahead of print. PMID: 36746413.

Bajema KL, Rowneki M, Berry K, Bohnert A, Bowling CB, Boyko EJ, Iwashyna TJ, Maciejewski ML, O'Hare AM, Osborne TF, Viglianti EM, Hynes DM, Ioannou GN. Rates of and Factors Associated With Primary and Booster COVID-19 Vaccine Receipt by US Veterans, December 2020 to June 2022. JAMA Netw Open. 2023 Feb 1;6(2):e2254387. doi: 10.1001/jamanetworkopen.2022.54387. PMID: 36729454.
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Ioannou GN, Horn CL, Kothari V, Yeh MM, Shyu I, Lee SP, Savard C. Genetic deletion or pharmacologic inhibition of the Nlrp3 Inflammasome did not ameliorate experimental NASH. J Lipid Res. 2023 Jan 11:100330. doi: 10.1016/j.jlr.2023.100330. Epub ahead of print. PMID: 36641116.
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Vutien P, Kim NJ, Merrill JO, Duncan MH, Ioannou GN, Collins SE. Extended-release Naltrexone Is Not Linked to Hepatotoxicity in Adults Experiencing Homelessness and Alcohol Use Disorder. J Addict Med. 2023 Jan 6. doi: 10.1097/ADM.0000000000001121. Epub ahead of print. PMID: 36728453.
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Bajema KL, Berry K, Streja E, Rajeevan N, Li Y, Yan L, Cunningham F, Hynes DM, Rowneki M, Bohnert A, Boyko EJ, Iwashyna TJ, Maciejewski ML, Osborne TF, Viglianti EM, Aslan M, Huang GD, Ioannou GN. Effectiveness of COVID-19 treatment with nirmatrelvir-ritonavir or molnupiravir among U.S. Veterans: target trial emulation studies with one-month and six-month outcomes. medRxiv [Preprint]. 2022 Dec 16:2022.12.05.22283134. doi: 10.1101/2022.12.05.22283134. PMCID: PMC9774229. PMID: 36561190.
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Admon AJ, Wander PL, Iwashyna TJ, Ioannou GN, Boyko EJ, Hynes DM, Bowling CB, Bohnert ASB, O'Hare AM, Smith VA, Pura J, Hebert PL, Wong ES, Niederhausen M, Maciejewski ML. Consensus elements for observational research on COVID-19-related long-term outcomes. Medicine (Baltimore). 2022 Nov 18;101(46):e31248. doi: 10.1097/MD.0000000000031248. PMID: 36401423.
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Bajema KL, Wang XQ, Hynes DM, Rowneki M, Hickok A, Cunningham F, Bohnert A, Boyko EJ, Iwashyna TJ, Maciejewski ML, Viglianti EM, Streja E, Yan L, Aslan M, Huang GD, Ioannou GN. Early Adoption of Anti-SARS-CoV-2 Pharmacotherapies Among US Veterans With Mild to Moderate COVID-19, January and February 2022. JAMA Netw Open. 2022 Nov 1;5(11):e2241434. doi: 10.1001/jamanetworkopen.2022.41434. PMID: 36367727
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O'Hare AM, Vig EK, Iwashyna TJ, Fox A, Taylor JS, Viglianti EM, Butler CR, Vranas KC, Helfand M, Tuepker A, Nugent SM, Winchell KA, Laundry RJ, Bowling CB, Hynes DM, Maciejewski ML, Bohnert ASB, Locke ER, Boyko EJ, Ioannou GN; VA COVID Observational Research Collaboratory (CORC). Complexity and Challenges of the Clinical Diagnosis and Management of Long COVID. JAMA Netw Open. 2022 Nov 1;5(11):e2240332. doi: 10.1001/jamanetworkopen.2022.40332. PMID: 36326761
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Jett KA, Baker ZN, Hossain A, Boulet A, Cobine PA, Ghosh S, Ng P, Yilmaz O, Barreto K, DeCoteau J, Mochoruk K, Ioannou GN, Savard C, Yuan S, Abdalla OH, Lowden C, Kim BE, Cheng HM, Battersby BJ, Gohil VM, Leary SC. Mitochondrial dysfunction reactivates α-fetoprotein expression that drives copper-dependent immunosuppression in mitochondrial disease models. J Clin Invest. 2022 Oct 27:e154684. doi: 10.1172/JCI154684. Epub ahead of print. PMID: 36301669
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Ioannou GN, Bohnert ASB, O'Hare AM, Boyko EJ, Maciejewski ML, Smith VA, Bowling CB, Viglianti E, Iwashyna TJ, Hynes DM, Berry K; COVID-19 Observational Research Collaboratory (CORC)*. Effectiveness of mRNA COVID-19 Vaccine Boosters Against Infection, Hospitalization, and Death: A Target Trial Emulation in the Omicron (B.1.1.529) Variant Era. Ann Intern Med. 2022 Oct 11. doi: 10.7326/M22-1856. Epub ahead of print. PMID: 36215715
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Moon AM, Ioannou GN. Moving Away From a One-Size-Fits-All Approach to Hepatocellular Carcinoma Surveillance. Am J Gastroenterol. 2022 Sep 1;117(9):1409-1411. doi: 10.14309/ajg.0000000000001897. Epub 2022 Jun 24. PMID: 35973179

Ioannou GN, Baraff A, Fox A, Shahoumian T, Hickok A, O'Hare AM, Bohnert ASB, Boyko EJ, Maciejewski ML, Bowling CB, Viglianti E, Iwashyna TJ, Hynes DM. Rates and Factors Associated With Documentation of Diagnostic Codes for Long COVID in the National Veterans Affairs Health Care System. JAMA Netw Open. 2022 Jul 1;5(7):e2224359. doi: 10.1001/jamanetworkopen.2022.24359. PMID: 35904783

Vutien P, Berry K, Feng Z, VoPham T, He Q, Green PK, Ioannou GN. Combining FIB-4 and liver stiffness into the FIB-5, a single model that accurately predicts complications of portal hypertension. Am J Gastroenterol. 2022 Jul 15. doi: 10.14309/ajg.0000000000001906. Epub ahead of print. PMID: 35849630

Kim NJ, Vutien P, Berry K, Ioannou GN. Hepatocellular carcinoma risk declines but remains high enough for screening in the first 7 years after HCV cure with DAAs in patients with cirrhosis or high FIB-4. Gastroenterology. 2022 Jun 28:S0016-5085(22)00681-3. doi: 10.1053/j.gastro.2022.06.057. Epub ahead of print. PMID: 35777481
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John BV, Barritt AS 4th, Moon A, Taddei TH, Kaplan DE, Dahman B; Contributors as part of the VOCAL COVID-19 investigators, Doshi A, Deng Y, Mansour N, Ioannou G, Martin P, Chao HH. Effectiveness of COVID-19 Viral Vector Ad.26.COV2.S Vaccine and Comparison with mRNA Vaccines in Cirrhosis. Clin Gastroenterol Hepatol. 2022 Jun 15:S1542-3565(22)00566-3. doi: 10.1016/j.cgh.2022.05.038. Epub ahead of print. PMCID: PMC9212810. PMID: 35716904
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VoPham T, Kim NJ, Berry K, Mendoza JA, Kaufman JD, Ioannou GN. PM2.5 air pollution exposure and nonalcoholic fatty liver disease in the Nationwide Inpatient Sample. Environ Res. 2022 Jun 7:113611. doi: 10.1016/j.envres.2022.113611. Epub ahead of print. PMID: 35688225
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Kim NJ, Vutien P, Cleveland E, Cravero A, Ioannou GN. Fibrosis-stage Specific Incidence of Hepatocellular Cancer after Hepatitis C Cure with Direct-Acting Antivirals: A Systematic Review & Meta-analysis. Clin Gastroenterol Hepatol. 2022 May 4:S1542-3565(22)00438-4. doi: 10.1016/j.cgh.2022.04.013. Epub ahead of print. PMID: 35525392
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Ioannou GN, Locke ER, Green PK, Berry K. Comparison of Moderna versus Pfizer-BioNTech COVID-19 vaccine outcomes: A target trial emulation study in the U.S. Veterans Affairs healthcare system. EClinicalMedicine. 2022 Mar 5;45:101326. doi: 10.1016/j.eclinm.2022.101326. PMCID: PMC8896984. PMID: 35261970
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Johnson KM, Newman KL, Berry K, Itani K, Wu P, Kamath PS, Harris AHS, Cornia PB, Green PK, Beste LA, Ioannou GN. Risk factors for adverse outcomes in emergency versus nonemergency open umbilical hernia repair and opportunities for elective repair in a national cohort of patients with cirrhosis. Surgery. 2022 Jan 17:S0039-6060(21)01191-0. doi: 10.1016/j.surg.2021.12.004. Epub ahead of print.
PMID: 35058058.
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Kim NJ, Rozenberg-Ben-Dror K, Jacob DA, Berry K, Ioannou GN. The COVID-19 pandemic highlights opportunities to improve hepatocellular carcinoma screening and diagnosis in a national health system: COVID-19 and HCC screening and diagnosis. Am J Gastroenterol. 2021 Dec 29. doi: 10.14309/ajg.0000000000001615. Epub ahead of print.
PMID: 35029156.

Ioannou GN, Locke ER, O'Hare AM, Bohnert ASB, Boyko EJ, Hynes DM, Berry K. COVID-19 Vaccination Effectiveness Against Infection or Death in a National U.S. Health Care System : A Target Trial Emulation Study. Ann Intern Med. 2021 Dec 21. doi: 10.7326/M21-3256. Epub ahead of print.
PMID: 34928700.

Beste LA, Zhang X, Su GL, Van T, Ioannou GN, Oselio B, Tincopa M, Liu B, Singal AG, Zhu J, Waljee AK. Adapted time-varying covariates Cox model for predicting future cirrhosis development performs well in a large hepatitis C cohort. BMC Med Inform Decis Mak. 2021 Dec 14;21(1):347. doi: 10.1186/s12911-021-01711-7.
PMID: 34903225.

Ioannou GN, Green P, Locke ER, Berry K. Factors associated with early receipt of COVID-19 vaccination and adherence to second dose in the Veterans Affairs healthcare system. PLoS One. 2021 Dec 1;16(12):e0259696. doi: 10.1371/journal.pone.0259696. PMCID: PMC8635372.
PMID: 34851970.

Ioannou GN, Lee SP, Linsley PS, Gersuk V, Yeh MM, Chen YY, Peng YJ, Dutta M, Mascarinas G, Molla B, Cui JY, Savard C. Pcsk9 Deletion Promotes Murine Nonalcoholic Steatohepatitis and Hepatic Carcinogenesis: Role of Cholesterol. Hepatol Commun. 2021 Nov 24. doi: 10.1002/hep4.1858. Epub ahead of print.
PMID: 34816633.

Asrani SK, Ghabril MS, Kuo A, Merriman RB, Morgan T, Parikh ND, Ovchinsky N, Kanwal F, Volk ML, Ho C, Serper M, Mehta S, Agopian V, Cabrera R, Chernyak V, El-Serag HB, Heimbach J, Ioannou GN, Kaplan D, Marrero J, Mehta N, Singal A, Salem R, Taddei T, Walling A, Tapper EB. Quality measures in HCC care by the Practice Metrics Committee of the American Association for the Study of Liver Diseases. Hepatology. 2021 Nov 15. doi: 10.1002/hep.32240. Epub ahead of print.
PMID: 34778999.

Ioannou GN, Ferguson JM, O'Hare AM, Bohnert ASB, Backus LI, Boyko EJ, Osborne TF, Maciejewski ML, Bowling CB, Hynes DM, Iwashyna TJ, Saysana M, Green P, Berry K. Changes in the associations of race and rurality with SARS-CoV-2 infection, mortality, and case fatality in the United States from February 2020 to March 2021: A population-based cohort study. PLoS Med. 2021 Oct 21;18(10):e1003807. doi: 10.1371/journal.pmed.1003807. PMCID: PMC8530298.
PMID: 34673772.

Pearson MM, Kim NJ, Berry K, Moon AM, Su F, Vutien P, Green PK, Williams EC, Ioannou GN. Associations Between Alcohol Use and Liver-Related Outcomes in a Large National Cohort of Patients With Cirrhosis. Hepatol Commun. 2021 Oct 3. doi: 10.1002/hep4.1776. Epub ahead of print.
PMID: 34601829.

D'Ambrosio R, Ioannou GN. Hepatocellular Carcinoma Risk, Outcomes, and Screening After Hepatitis C Eradication. Hepatol Commun. 2021 Sep;5(9):1465-1468. doi: 10.1002/hep4.1733.
PMID: 34510832.

Ioannou GN. Epidemiology and risk-stratification of NAFLD-associated HCC. J Hepatol. 2021 Aug 25:S0168-8278(21)02007-9. doi: 10.1016/j.jhep.2021.08.012. Epub ahead of print.
PMID: 34453963.

Horn CL, Morales AL, Savard C, Farrell GC, Ioannou GN. Role of Cholesterol-Associated Steatohepatitis in the Development of NASH. Hepatol Commun. 2021 Aug 24. doi: 10.1002/hep4.1801. Epub ahead of print.
PMID: 34558856.

O'Hare AM, Berry K, Fan VS, Crothers K, Eastment MC, Dominitz JA, Shah JA, Green P, Locke E, Ioannou GN. Age differences in the association of comorbid burden with adverse outcomes in SARS-CoV-2. BMC Geriatr. 2021 Jul 6;21(1):415. doi: 10.1186/s12877-021-02340-5. PMCID: PMC8258273.
PMID: 34229623.

Vutien P, Ioannou GN. Editorial: is there a 'precursor' HCC lesion and can it be detected by hepatobiliary contrast-enhanced magnetic resonance imaging? Aliment Pharmacol Ther. 2021 Jul;54(2):202-203. doi: 10.1111/apt.16455.
PMID: 34170532

Ioannou GN, O'Hare AM, Berry K, Fan VS, Crothers K, Eastment MC, Locke E, Green P, Shah JA, Dominitz JA. Trends over time in the risk of adverse outcomes among patients with SARS-CoV-2 infection. Clin Infect Dis. 2021 May 11:ciab419. doi: 10.1093/cid/ciab419. Epub ahead of print.
PMID: 33973000

Ioannou GN, Green P, Fan VS, Dominitz JA, O'Hare AM, Backus LI, Locke E, Eastment MC, Osborne TF, Ioannou NG, Berry K. Development of COVIDVax Model to Estimate the Risk of SARS-CoV-2-Related Death Among 7.6 Million US Veterans for Use in Vaccination Prioritization. JAMA Netw Open. 2021 Apr 1;4(4):e214347. doi: 10.1001/jamanetworkopen.2021.4347.
PMID: 33822066

Kaplan DE, Mehta R, Garcia-Tsao G, Albrecht J, Aytaman A, Baffy G, Bajaj J, Hernaez R, Hunt K, Ioannou G, Johnson K, Kanwal F, Lee TH, Monto A, Pandya P, Schaubel D, Taddei TH. SACRED: Effect of simvastatin on hepatic decompensation and death in subjects with high-risk compensated cirrhosis: Statins and Cirrhosis: Reducing Events of Decompensation. Contemp Clin Trials. 2021 Mar 24;104:106367. doi: 10.1016/j.cct.2021.106367. Epub ahead of print.
PMID: 33771685



Eastment MC, Berry K, Locke E, Green P, O'Hare A, Crothers K, Dominitz J, Fan VS, Shah JA, Ioannou GN. Body mass index (BMI) and outcomes of SARS-CoV-2 among US veterans. Obesity (Silver Spring). 2020 Dec 18. doi: 10.1002/oby.23111. Epub ahead of print.
PMID: 33336934

Mahmud N, Fricker Z, Hubbard RA, Ioannou GN, Lewis JD, Taddei TH, Rothstein KD, Serper M, Goldberg DS, Kaplan DE. Risk Prediction Models for Post-Operative Mortality in Patients With Cirrhosis. Hepatology. 2021 Jan;73(1):204-218. doi: 10.1002/hep.31558. Epub 2020 Dec 10. PMCID: PMC7902392.
PMID: 32939786

Ioannou GN. HCC surveillance after SVR in patients with F3/F4 fibrosis. J Hepatol. 2020 Dec 7:S0168-8278(20)33730-2. doi: 10.1016/j.jhep.2020.10.016. Epub ahead of print.
PMID: 33303216

Kim NJ, Jacob DA, Ioannou GN, John BV, Rogal S, Rozenberg-Ben-Dror K. Rates and Predictors of Undergoing Different Hepatocellular Carcinoma Screening Tests in Patients With Cirrhosis. Am J Gastroenterol. 2020 Nov 26. doi: 10.14309/ajg.0000000000001000. Epub ahead of print.
PMID: 33252455

Su F, Weiss NS, Beste LA, Moon AM, Jin GY, Green P, Berry K, Ioannou GN. Screening is associated with a lower risk of hepatocellular carcinoma-related mortality in patients with chronic hepatitis B. J Hepatol. 2020 Nov 24:S0168-8278(20)33807-1. doi: 10.1016/j.jhep.2020.11.023. Epub ahead of print.
PMID: 33245934

Kim NJ, Ioannou GN. Reply. Clin Gastroenterol Hepatol. 2020 Nov 18:S1542-3565(20)31556-1. doi: 10.1016/j.cgh.2020.11.022. Epub ahead of print.
PMID: 33220525

Ioannou GN, Liang PS, Locke E, Green P, Berry K, O'Hare AM, Shah JA, Crothers K, Eastment MC, Fan VS, Dominitz JA. Cirrhosis and SARS-CoV-2 infection in US Veterans: risk of infection, hospitalization, ventilation and mortality. Hepatology. 2020 Nov 21. doi: 10.1002/hep.31649. Epub ahead of print.
PMID: 33219546

Cravero AL, Kim NJ, Feld LD, Berry K, Rabiee A, Bazarbashi N, Bassin S, Lee TH, Moon AM, Qi X, Liang PS, Aby ES, Khan MQ, Young KJ, Patel A, Wijarnpreecha K, Kobeissy A, Hashim A, Houser A, Ioannou GN. Impact of exposure to patients with COVID-19 on residents and fellows: an international survey of 1420 trainees. Postgrad Med J. 2020 Oct 21:postgradmedj-2020-138789. doi: 10.1136/postgradmedj-2020-138789. Epub ahead of print.
PMID: 33087533

Vutien P, Kim NJ, Moon AM, Pearson M, Su F, Berry K, Gelman H, Ioannou GN. Fibroscan liver stiffness after anti-viral treatment for hepatitis C is independently associated with adverse outcomes. Aliment Pharmacol Ther. 2020 Dec;52(11-12):1717-1727. doi: 10.1111/apt.16092. Epub 2020 Sep 20.
PMID: 32951216

Kim NJ, Rozenberg-Ben-Dror K, Jacob DA, Rich N, Singal AG, Aby ES, Yang JD, Nguyen V, Pillai A, Fuchs M, Moon AM, Shroff H, Agarwal PD, Perumalswami P, Chandna S, Zhou K, Patel YA, Latt NL, Wong R, Duarte-Rojo A, Lindenmeyer CC, Frenette C, Ge J, Mehta N, Yao F, Benhammou JN, Bloom PP, Leise M, Kim HS, Levy C, Barnard A, Khalili M, Ioannou GN. Provider Attitudes Toward Risk-Based Hepatocellular Carcinoma Surveillance in Patients With Cirrhosis in the United States. Clin Gastroenterol Hepatol. 2020 Sep 12:S1542-3565(20)31272-6. doi: 10.1016/j.cgh.2020.09.015. Epub ahead of print.
PMID: 32927050

Benhammou JN, Moon AM, Pisegna JR, Su F, Vutien P, Moylan CA, Ioannou GN. Nonalcoholic Fatty Liver Disease Risk Factors Affect Liver-Related Outcomes After Direct-Acting Antiviral Treatment for Hepatitis C. Dig Dis Sci. 2020 Jul 11:10.1007/s10620-020-06457-2. doi: 10.1007/s10620-020-06457-2. Epub ahead of print. PMCID: PMC7854862.
PMID: 32654086

Ioannou GN, Nagana Gowda GA, Djukovic D, Raftery D. Distinguishing NASH Histological Severity Using a Multiplatform Metabolomics Approach. Metabolites. 2020 Apr 24;10(4):168. doi: 10.3390/metabo10040168. PMCID: PMC7240949.
PMID: 32344559



Moon AM, Green PK, Rockey DC, Berry K, Ioannou GN. Hepatitis C eradication with direct-acting anti-virals reduces the risk of variceal bleeding. Aliment Pharmacol Ther. 2020 Feb;51(3):364-373. doi: 10.1111/apt.15586. Epub 2019 Nov 27. PMCID: PMC7416556.
PMID: 31773763

Tapper EB, Parikh ND, Green PK, Berry K, Waljee AK, Moon AM, Ioannou GN. Reduced Incidence of Hepatic Encephalopathy and Higher Odds of Resolution Associated With Eradication of HCV Infection. Clin Gastroenterol Hepatol. 2020 May;18(5):1197-1206.e7. doi: 10.1016/j.cgh.2019.09.033. Epub 2019 Oct 4. PMCID: PMC7124980.
PMID: 31589975

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Grants & Funding


Development and Validation of a Cirrhosis-specific Surgical Risk Calculator (C-SuRC)

NIH website:

Evaluating a novel, portable, self-administered device (Flicker-App) that measures critical flicker frequency as a test for minimal hepatic encephalopathy in cirrhosis

NIH website:

Does Screening for HCC in Cirrhotic Patients Reduce HCC-related Mortality?

NIH website: