Study design and population
This retrospective study was carried out from January 2014 to November 2018 in Montpellier University Hospital, France. In this tertiary care institution, all children with an IH requiring a medical treatment with a beta-blocker are systematically hospitalized for treatment initiation. In this study, the hospital discharge database (PMSI, Programme de Medicalisation des Systemes d’Information) was used for patients screening. The PMSI is a mandatory national database linked to the social security, in which all hospitalizations are automatically and prospectively registered. This database uses a standardized diagnosis coding from the 10th revision of the International Classification of Diseases (ICD-10). The code associated to the term “haemangioma” (D13) was used to screen patients and finally only children <2 years old treated with Hemangiol® were included in the final analysis.