Statistical methods
INFLUENZA
A VH score was constructed at T0 and T1 by summing the 13 PACV items by Opel's approach [We used chi-squared tests (categorical variables) and Wilcoxon rank-sum tests (continuous scores) for baseline comparisons. For comparing the impact of the MI-based intervention with that of the control on both VH and VI scores, we computed mixed models with random intercepts to create D-I-D models. These allow changes over time (pre- and post-intervention) of an outcome to be compared between two groups, while taking into account the repeated nature of the data [The overall D-I-D models were performed without covariates and then adjusted for maternity ward, age, education level, perceived financial situation, birth rank of the newborn and influenza vaccination during pregnancy. Analyses were performed by intention-to-treat (ITT): all patients who agreed to participate and completed the pre-questionnaire (T0) were included, with missing post-questionnaire (T1) data handled by the mixed model without imputation [