Transition from child- to adult-orientated care for children with long-term health conditions: a process, not an event.

Long-term health conditions in childhood include both congenital conditions and acquired diseases. Children with long-term health conditions face issues and potential secondary problems that are different from those of adults with chronic diseases. Transition to adult-orientated care for such children and adolescents is a major challenge. Transition needs to be prepared for and planned. A variety of possible transition models exists, depending on circumstances.