p<0.001) as well as dabigatran 2×150 mg (X 2 (1, N = 40) = 5.95, p = 0.015) and incorrect dosing. A risk factor significantly related with incorrect dosing was age above 80 years (X 2 (1, N = 351) = 7.0, p = 0.008). 45.9% of dosing errors were corrected following a pharmaceutical intervention. A common reason given for incorrect dosing was 'unstable renal function'. Conclusion and relevanceThis study showed that DOAC dosing errors are frequent and pharmaceutical interventions can contribute to a reduction of these errors. Special caution is needed in elderly patients. Measures to increase acceptance rate need to be further investigated.