Heterogeneity after harmonisation: a retrospective cohort study of bleeding and stroke risk after the introduction of direct oral anticoagulants in four Western European countries.

Stroke prevention therapy improved from 2012 to 2017 with a corresponding reduction in stroke risk without increasing the risk of bleeding in all countries, except Scotland. Heterogeneity that remains after methodological harmonisation can be informative of the underlying population and database. This article is protected by copyright. All rights reserved.