Non-alcoholic fatty liver disease (NAFLD) prevalence in Latin American and the Caribbean: Protocol for a systematic review

ABSTRACT Background Non-alcoholic fatty liver disease (NAFLD) is the most common worldwide cause of chronic liver disease and it carries a significant economic burden for the healthcare system. The worldwide prevalence of NAFLD appears to be 25%, with the highest rates in Latin America and the Caribbean (LAC) and the middle west. Prevalence of NAFLD in LAC has not been well represented in multiple global meta-analyses because they did not include regional search engines or excluded papers in Spanish. Furthermore, older estimates may not represent the current epidemiological situation given the recent rise of several risk factors like obesity, unhealthy diet and lifestyles in LAC. Objective To estimate the prevalence of NAFLD in the general adult population of LAC. Methods Systematic review and meta-analysis. We will conduct a search in OVID (MEDLINE, Embase, Global Health), Cochrane Library, and LILACS. Search terms include those related to non-alcoholic fatty liver disease, along with countries in LAC. We seek observational studies with a random sample of the general population, closed populations, and patients; results will be presented for each of these groups. Titles and abstracts will be screened by two reviewers independently. After the screening phase, we will download the full-text of the selected publications and two reviewers will comprehensively read these papers. If there is any discrepancy in any of these two selection phases, it will be solved by consensus by the two reviewers or by a third party. An extraction data form in a spreadsheet will be developed and tested with a random sample of five selected studies. The data extracted will include study details, sample size, method of NAFLD diagnosis and prevalence of NAFLD. Data extraction will be conducted by two reviewers independently. We will use the risk of bias tool proposed by Hoy and colleagues. We will report the main features of the selected reports in tables, this will include the prevalence estimates. We will pool the prevalence estimates. We will only conduct the meta-analysis if there are three or more individual estimates and there is not large heterogeneity amongst them. We will conduct all statistical analyses using Stata 16.0 Conclusions This systematic review and meta-analysis will provide updated evidence about the prevalence of NAFLD in LAC. Thereby, we will increase NAFLD awareness as a public health problem in LAC, and our results can inform strategies and interventions to reduce NAFLD burden in LAC. We will also pinpoint research needs and discuss future steps so that more robust evidence about NAFLD becomes available in LAC.