1 Necker Hospital for Sick Children, Inserm U1153, Paris-Descartes University, Paris, France.
2 King's College London, London, United Kingdom.
3 Association Clinique et Thérapeutique Infantile du Val-de-Marne, Saint-Maur-des-Fossés, Association Française de Pédiatrie Ambulatoire, Chambéry, France.
4 Department of Health Science, University Hospital Anna Meyer, Florence, Italy.
5 Necker Hospital for Sick Children, Inserm U1153, Paris-Descartes University, Paris, France. martin.chalumeau@inserm.fr.