Hemolytic anemia (HA) is a group of rare diseases that can be congenital such as thalassemia, sickle-cell anemia, enzyme-deficiency hemolytic anemia and spherocytosis, or acquired such as autoimmune hemolytic anemia (AIHA) [1]. Few epidemiological studies have been conducted on HA, based on small retrospective cohorts. Therefore, large studies are needed to improve the knowledge of these diseases and their management. National databases are useful data sources to assess the epidemiology and the management of these rare diseases.
