(P-188) The Global Burden of Upper and Lower Gastrointestinal Bleeding in General Population: A Systematic Review

Background: Gastrointestinal bleeding (GIB) is a common and life-threatening clinical event with no published information of disease burden worldwide. Results of this review provide an overview of disease distribution at a global level, while enabling drug-induced risk of bleeding to be placed in context.

Objectives: The objective was to summarize rates of incidence, mortality, and case fatality of upper and lower GIB in adults. Secondary objective was to report the proportion of recurrent bleeds.

Methods: Embase and MEDLINE were queried from inception to September 17, 2019. Titles and abstracts of retrieved studies were reviewed independently by two reviewers. Population-based studies reporting incidence, mortality, and/or case fatality rates due to upper and/or lower GIB in general adult population were included. Interventional studies, studies with patient subgroups, and studies that investigated etiologic subgroups of GIB were excluded. Demographics, population size, study design, location and primary data source were extracted by the first reviewer. Second reviewer performed data quality check. Primary outcomes were incidence and mortality per 100,000 person-years, and case fatality rate (%). Secondary outcome was recurrence (%). Where reported, temporal trends of incidence rates were graphed. Risk of bias and methodological quality were assessed at study level using JBI Critical Appraisal Checklist and STROBE guidelines, respectively.

Results: Of 4,203 identified records, 41 studies were included with data from a total of 4,162,067 patients worldwide. Of these studies, 33 reported rates for upper GIB, 4 for lower GIB and 4 presented data on both. Available data mainly from Europe (25) and from North America (8). There were 19 studies with retrospective data, 21 studies with prospective data and one study used both. The mean/median age range was 44.3-76.5 years. Reported incidence was 15.0-172.0/100,000 person-years for upper and 20.5-87.0/100,000 for lower GIB. Mortality data were only available from 6 studies for upper GIB, ranging from 0.88-9.75 per 100,000, and from 1 lower GIB study at 1.4 per 100,000 person-years. Case fatality rates were 0.71-8.1% for upper and 0.5-8.0% for lower GIB. Classification bias, missing data and the sample size were the main areas of risk.

Conclusions: Overall, high variability in the estimates demonstrate the need for standardisation across studies on GIB. This heterogeneity can be attributed to poor data collection and problems with disease classification across studies. Lack of emphasis on LGIB and mortality estimates need to be addressed in further research.