Background This study aimed to evaluate racial differences in bleeding incidence by conducting an ecological epidemiological study using data from Korea and the United Kingdom.

Methods We included healthy participants from the Korean National Health Insurance Service-Health Screening and the UK Biobank who underwent health examinations between 2006 and 2010 and had no comorbidities or history of medication use. Finally, 112,750 East Asians (50.7% men, mean age 52.6 years) and 210,995 Caucasians (44.7% men, mean age 55.0 years) were analyzed. The primary outcome was composed of intracranial hemorrhage (ICH) and bleeding from the gastrointestinal, respiratory, and genitourinary systems.

Results During the follow-up, primary outcome events occurred in 2,110 East Asians and in 6,515 Caucasians. East Asians had a 38% lower 5-year incidence rate compared with Caucasians (3.88 vs. 6.29 per 1,000 person-years; incidence rate ratio [IRR]: 0.62, 95% confidence interval [CI]: 0.59–0.65). East Asians showed a lower incidence of major bleeding (IRR: 0.86, 95% CI: 0.81–0.91), bleeding from the gastrointestinal (IRR: 0.53, 95% CI: 0.49–0.56), and genitourinary systems (IRR: 0.49, 95% CI: 0.44–0.53) compared with Caucasians. The incidence rates of ICH (IRR: 3.20, 95% CI: 2.67–3.84) and bleeding from the respiratory system (IRR: 1.28, 95% CI: 1.11–1.47) were higher in East Asians. Notably, East Asians consuming alcohol ≥3 times/week showed a higher incidence of the primary outcome than Caucasians (IRR: 1.12, 95% CI: 1.01–1.25).

Conclusion This ecological study revealed significant racial differences in bleeding incidence, influenced by anatomical sites and lifestyle habits, underscoring the need for tailored approaches in bleeding management based on race.