Systematic Reviews
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Apr 27, 2023; 15(4): 723-739
Published online Apr 27, 2023. doi: 10.4240/wjgs.v15.i4.723
The global epidemiology of upper and lower gastrointestinal bleeding in general population: A systematic review
Şiir Su Saydam, Megan Molnar, Pareen Vora
Şiir Su Saydam, Megan Molnar, Pareen Vora, Integrated Evidence Generation, Bayer AG, Berlin 13353, Germany
Author contributions: Saydam SS and Vora P designed the research study; Saydam SS, Molnar M and Vora P performed the research; Saydam SS analyzed the data and wrote the manuscript; All authors have read and approved the final manuscript.
Conflict-of-interest statement: Saydam SS and Vora P are employees of Bayer AG. Molnar M was an employee of Bayer AG at the time the study was carried out.
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Pareen Vora, PhD, Director, Integrated Evidence Generation, Bayer AG, Muellerstr. 178, Berlin 13353, Germany. pareen.vora@bayer.com
Received: October 19, 2022
Peer-review started: October 19, 2022
First decision: January 3, 2023
Revised: January 20, 2023
Accepted: March 8, 2023
Article in press: March 8, 2023
Published online: April 27, 2023
ARTICLE HIGHLIGHTS
Research background

Gastrointestinal bleeding (GIB) can be a life-threatening medical event; however, reviews on the overall global epidemiology of the condition are lacking. Previous reviews have instead covered risk factors or prediction scores for GIB or have described the epidemiology of GIB arising from specific etiologies.

Research motivation

No overarching review on the broad and long-term worldwide epidemiology of GIB currently exists. A systematic review would be highly informative for future research in the field to provide a robust overview of GIB incidence, mortality and case-fatality.

Research objectives

The objective was to perform a systematic review of the long-term global epidemiology of both upper GIB (UGIB) and lower GIB (LGIB), covering incidence, mortality and case-fatality of the condition. Such population-based estimates would enable trends over time, and by geography, to be observed, which could have been influenced by changing medical practices, and it would also help identify areas where data are plentiful or lacking.

Research methods

A search strategy using relevant keywords was conducted using EMBASE® and MEDLINE from 1 January 1965 to 17 September 2019. Conference abstracts, editorials, letters, notes, and short surveys were excluded, as well as randomized controlled trials and interventional studies (as these are performed among selected individuals, and do not enable population-based epidemiological estimates to be calculated). Two authors undertook the screening of titles, abstracts and full-texts of papers. Data on the epidemiological variables of interest were extracted.

Research results

Thirty-six studies were included. The main findings were that the incidence of UGIB ranged from 15.0 to 172.0/100000 person-years and the incidence of LGIB ranged from 20.5 to 87.0/100000 person-years, although data for LGIB were more limited than for UGIB. Temporal trends were described in 13 studies and showed an overall decline in upper GIB incidence over time. UGIB mortality rates ranged from 0.9 to 9.8/100000 person-years, and from 0.8 to 3.5/100000 person-years for LGIB; case-fatality rate ranged from 0.7 to 4.8% for UGIB and 0.5 to 8.0% for LGIB.

Research conclusions

Substantial variation exists in estimates of GIB epidemiology worldwide, likely due to high heterogeneity between studies, highlighting a lack of consistency in GIB definitions. As data on LGIB epidemiology were sparse, this area should be further explored in future research.

Research perspectives

The proposed direction of future research would be to obtain contemporary estimates of UGIB and, especially LGIB epidemiology from large, high quality, population-based studies with good case ascertainment and case validation.