Background The pediatric-adult care transition is a risk-disrupting time for patients with chronic disease. This care transition takes place during adolescence; a period of psychological upheavals and adaptations of family roles. During this period, medication adherence is non-optimal and absenteeism at medical appointments is high.

Sickle cell disease (SCD) is the first genetic disease detected in France. It is chronic disease characterized by frequent painful vaso-occlusive crises (VOC) requiring emergency hospitalization when they are severe. Other serious complications are acute chest syndromes (ACS) and stroke.

In order to improve the health status of teenagers with sickle cell disease, it is necessary to anticipate this care transition and to involve the pediatric and adult sectors. The biopsychosocial health approach and the Social-Ecological Model of Adolescent and Young Adult Readiness to Transition (SMART) describe a care transition integrating bioclinical and psychosocial factors such as integration of the patient's family, education on disease and therapeutics, psychological management of pain and medico-social orientation.

The pediatric-adult transition program proposed is based on this biopsychosocial approach. It aims to improve the health status of adolescents with SCD, their quality of life and the use of health care service.

Objective of the study To assess the impact of a pediatric-adult transition program on the incidence of sickle-cell-related complications leading to hospitalization on 24-months after transfer to the adult sector.

The evaluation focuses on severe complications leading to hospitalization, such as VOC, ACS, and stroke.

Study design Multicenter Open-label individual Randomized Controlled Trial Population : Patients aged at least 16 years old with sickle cell disease, and their parents (or legal representatives Number of subject : 196 patients (98 patients by arm) The study will last 24 months Expected results For patients and families Better health and quality of life for patients is expected, including better use of medical care after the transition program. It is also expected a better experience of the pediatric-adult care transition and indirectly a better experience of intrafamilial relations.

For health professionals This project is expected to provide solutions to improve the pediatric-adult care transition of patients with chronic disease. Indeed, the methodological quality of the study will make it possible to evaluate the efficiency of the proposed program, to possibly adapt it and test it to other chronic diseases presenting the same care transition problematic.

In terms of public health SCD mainly affects populations of sub-Saharan origin, with low visibility and high social vulnerability. By focusing on this population, this project will reduce the social inequalities in health, experienced by patients with SCD and their families.

By improving the health, quality of life and care of patients with SCD, this project is expected to decrease the cost of the pediatric-adult care transition period.

Inclusion Criteria:

For patients :

• Age: 16-17 years,
• With major sickle cell syndrome, defined by hemoglobinopathy of homozygosity SS, or double heterozygosity SC or Sβ-thalassemia,
• Benefiting from social insurance of the type "Affection of long duration" (ALD).

For family members :

• Included children's parents or legal representatives,
• Accepting to participate in the study and having signed the informed consent.

Exclusion Criteria:

• Presenting a cognitive or psychiatric disorder known and major that may hinder interventions or evaluation, the judgment of the investigator, and / or having a family history with this type of disorders,
• Cured of SCD by an allograft of hematopoietic stem cells.