Trial design
This study is a multicenter, cluster-randomized controlled trial with two evenly randomized arms. A cluster is defined as the total recruited patients per praxis. Data were collected at three timepoints: pre-intervention (baseline, T0), at 6 months (T1) and 12 months (T2). The study was conducted in general practices in the German regions of Middle- and North-Hessen and Ruhr and Rhine valley in North Rhine-Westphalia. Three study centers were involved: Department of General Practice of Marburg University; Institute of General Practice of Heinrich-Heine-University Düsseldorf; and Institute of General Practice and Primary Care of Witten/Herdecke University. The study protocol was published by Rieckert et al.