Afonso A, Schmiedl S, Becker C, Tcherny-Lessenot S, Primatesta P, Plana E, Souverein P, Wang Y, Korevaar JC, Hasford J, Reynolds R, de Groot MC, Schlienger R, Klungel O, Rottenkolber M. A methodological comparison of two European primary care databases and replication in a US claims database: inhaled long-acting beta-2-agonists and the risk of acute myocardial infarction. Eur J Clin Pharmacol. 2016 Sep;72(9):1105-16.