Study selection and data collection

Published studies of patients with NAFLD or NASH receiving any therapeutic intervention were included. NAFLD and NASH were independently defined by each study, usually either by imaging or histology.

Randomized controlled trials (RCTs) or prospective cohort studies conducted in the United States and Canada with human subjects aged 18 years or older were included. Retrospective studies, case-control, case series, case reports, reviews, and studies with non-human subjects or non-English language were excluded. Three investigators (Patel P, Muller C and Paul S) reviewed articles for study inclusion with discrepancies resolved by consensus. All data were extracted by 1 researcher and verified by another independent researcher and included study author, country, publication date, study design, intervention, sex, age, and race and/or ethnicity. Enrollment demographic information regarding race and ethnicity, when available, was recorded as defined in each individual study. For the purposes of analysis, ethnicity referred to designations of “Hispanic” or “non-Hispanic”, reported along with an independent racial designation for each participant.

An assessment of risk of bias was not performed as we had a heterogenous inclusion criteria, and a risk assessment is not applicable to our study design. Additionally, given the framework of our research question, we have demonstrated that these studies are, in fact, biased towards patient selection.