Knowledge-related outcomes
The Cronbach’s alpha for knowledge was 0.61. The mean knowledge score of the total group was 10.2 at t0, with almost equal scores in the IG and CG (10.2 vs. 10.1; p = 0.960). At t1, the mean knowledge score in the IG had increased to 11.3. Knowledge level in the CG had increased to 10.5 at t1. As Fig. 
Knowledge-related outcomes at baseline (t0) and three months (t1) after study inclusionKnowledge level was determined by measuring the number of correctly rated statements per participant at baseline (t0) and three months (t1) after study inclusion. Mean scores for the IG and the CG are shown. P-values were determined by two-sided Mann-Whitney-U-test. The number of participants was as follows: at t0 the IG had n = 215, the CG n = 201; at t1 the IG had n = 205, the CG n = 191