Methods for additional analyses (e.g., subgroup analyses) {20b}
The difference in percentages between the two groups will be determined by a chi-square test, thus allowing the main objective to be met. This result will be adjusted according to several criteria, in particular two of them: a center effect, a baseline effect, and an effect of the degree of experience of the nurse.Indeed, the analysis of cluster trials is more complex than the analysis of trials with individual randomization units. The analysis will therefore also be performed at the cluster level using the Health French Authority of June 2007 cluster (methodological guide downloadable from 