1. Department of the Vodafone Foundation Chair for Children`s Pain Therapy and Paediatric Palliative Care, Witten/Herdecke University, Faculty of Health, School of Medicine, Germany.
2. German Paediatric Pain Centre, Children`s and Adolescents' Hospital, Datteln, Germany.
3. Starship Children's Hospital, Grafton, Auckland, New Zealand.
4. Faculty of Nursing, University of Athens, Greece.
5. UCL Institute of Child Health, London, UK and Rutgers University, Camden, New Jersey.