Sample size
The number of cases was calculated on the basis of the number of emergency contacts after twelve months (primary outcome). Based on literature estimates, it was assumed that the expected number of 2.7 emergency contacts per patient per year could be reduced by approximately 15% to 2.295 emergency contacts. The alpha was assumed to be 0.05. Taking into account the cluster effect and a dropout of 30% and a target power of 80%, this results in 817 patients in the intervention group and 1634 patients in the control group.