Evaluation of bleeding-related adverse events following acupuncture treatment in patients on anticoagulant or antiplatelet drugs: A prospective observational study.

•The relative risk of exposure of the unexposed group was 0.87 (95% CI 0.69–1.10), indicating that exposure to anticoagulants or antiplatelet agents did not increase the incidence of bleeding-related adverse events.•In the additional analysis using the number of acupuncture needles, the relative risk of exposure of the unexposed group was 0.89 (95% CI 0.70–1.13), with no statistically significant difference.•In multivariable analysis, thickness of needle only increased risk of bleeding, and subgroup analysis showed that taking the drugs did not increase the risk of bleeding in any of the body regions.•All bleeding-related adverse events were asymptomatic and insignificant.