The global epidemiology of upper and lower gastrointestinal bleeding in general population: A systematic review.

BACKGROUND: Gastrointestinal bleeding (GIB) is a common and potentially life-threatening clinical event. To date, the literature on the long-term global epidemiology of GIB has not been systematically reviewed. AIM: To systematically review the published literature on the worldwide epidemiology of upper and lower GIB. METHODS: EMBASE® and MEDLINE were queried from 01 January 1965 to September 17, 2019 to identify population-based studies reporting incidence, mortality, or case-fatality rates of upper GIB (UGIB) or lower GIB (LGIB) in the general adult population, worldwide. Relevant outcome data were extracted and summarized (including data on rebleeding following initial occurrence of GIB when available). All included studies were assessed for risk of bias based upon reporting guidelines. RESULTS: Of 4203 retrieved database hits, 41 studies were included, comprising a total of around 4.1 million patients with GIB worldwide from 1980-2012. Thirty-three studies reported rates for UGIB, four for LGIB, and four presented data on both. Incidence rates ranged from 15.0 to 172.0/100000 person-years for UGIB, and from 20.5 to 87.0/100000 person-years for LGIB. Thirteen studies reported on temporal trends, generally showing an overall decline in UGIB incidence over time, although a slight increase between 2003 and 2005 followed by a decline was shown in 5/13 studies. GIB-related mortality data were available from six studies for UGIB, with rates ranging from 0.9 to 9.8/100000 person-years, and from three studies for LGIB, with rates ranging from 0.8 to 3.5/100000 person-years. Case-fatality rate ranged from 0.7% to 4.8% for UGIB and 0.5% to 8.0% for LGIB. Rates of rebleeding ranged from 7.3% to 32.5% for UGIB and from 6.7% to 13.5% for LGIB. Two main areas of potential bias were the differences in the operational GIB definition used and inadequate information on how missing data were handled. CONCLUSION: Wide variation was seen in estimates of GIB epidemiology, likely due to high heterogeneity between studies however, UGIB showed a decreasing trend over the years. Epidemiological data were more widely available for UGIB than for LGIB.