Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Hepatol. Aug 27, 2020; 12(8): 506-518
Published online Aug 27, 2020. doi: 10.4254/wjh.v12.i8.506
Racial disparities in nonalcoholic fatty liver disease clinical trial enrollment: A systematic review and meta-analysis
Parita Patel, Charles Muller, Sonali Paul
Parita Patel, Charles Muller, Sonali Paul, Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago Medical Center, Chicago, IL 60637, United States
Author contributions: Patel P and Muller C contributed to this manuscript equally; Paul S designed the study; Patel P and Muller C collected clinical data; Muller C conducted statistical analysis; Patel P, Muller C, and Paul S prepared and approved the final version of the manuscript.
Conflict-of-interest statement: The authors deny any conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See:
Corresponding author: Sonali Paul, MD, MSc, Assistant Professor, Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago Medical Center, 5841 S Maryland Avenue, MC 4076, Chicago, IL 60637, United States.
Received: April 13, 2020
Peer-review started: April 13, 2020
First decision: April 29, 2020
Revised: July 9, 2020
Accepted: July 26, 2020
Article in press: July 26, 2020
Published online: August 27, 2020

Non-alcoholic fatty liver disease (NAFLD) has a heterogeneous distribution across racial and ethnic groups, with a disproportionate burden among Hispanics. Although there are currently no approved therapies for treatment of NAFLD, several therapies have been investigated in clinical trials.


To analyze the inclusion of racial and ethnic minority groups in clinical trials for NAFLD.


We performed a systematic review of North American, English-language, prospective studies for NAFLD therapies published from 2005 to 2019. Racial and ethnic enrollment data were recorded for each eligible study. Meta-analysis was performed to compute pooled prevalence of different racial and ethnic groups, followed by further subgroup analyses. These analyses were based on diagnosis of non-alcoholic steatohepatitis (NASH) and timing of study on enrollment by ethnicity. Descriptive statistics were performed to compare racial and ethnic study enrollment to previously reported NAFLD population prevalence.


Thirty-eight studies met criteria for inclusion in the systematic review. When reported, median age of enrolled subjects was 49 years (range 41.5-58) with 56% female participants. NAFLD was defined through biopsy findings in 79% (n = 30) of the studies. Of the included articles, treatment modalities ranged from medications (n = 28, 74%), lifestyle interventions (n = 5, 13%), bariatric surgery (n = 4, 11%) and phlebotomy (n = 1, 2%). Twenty-eight studies (73%) included racial and/or ethnic demographic information, while only 17 (45%) included information regarding Hispanic participation. Of the 2983 patients enrolled in all eligible trials, a total of only 346 (11.6%) Hispanic participants was reported. Meta-analysis revealed a pooled Hispanic prevalence of 24.3% (95% confidence interval 16.6-32.0, I2 94.6%) among studies documenting Hispanic enrollment. Hispanic enrollment increased over time from 15% from 2005-2014 to 37% from 2015-2019.


In a meta-analysis of NAFLD trials, documentation of racial/ethnic demographic data occurred in less than half of studies. Standardization of reporting of race/ethnicity and targeted interventions toward minority recruitment are needed to improve diversity of enrollment.

Keywords: Non-alcoholic fatty liver disease, Non-alcoholic steatohepatitis, Hispanic, Racial disparities, Meta-analysis

Core tip: The Hispanic population in the United States is disproportionately affected by non-alcoholic fatty liver disease (NAFLD). Currently, there is no Food and Drug Administration approved treatment for this disease, but several clinical trials are investigating new potential therapies. This study evaluates the inclusion of race and ethnicity in the enrollment of these trials. In a systemic review and meta-analysis of clinical trials for treatment of NAFLD, 44% of eligible trials reported data on race and ethnicity. Despite a high burden of disease, Hispanic participation remained low. Future targeted interventions must take place to increase the enrollment of diverse and representative study populations in clinical trials.