1. Norwegian Institute of Public Health; Oslo Norway
2. TRS National Resource Centre for Rare Disorders; Sunnaas Rehabilitation Hospital; Nesoddtangen Norway
3. Department of Health Promotion and Development; University of Bergen; Bergen Norway
4. Health Systems Research Unit; South African Medical Research Council; Cape Town South Africa
5. Centre for Infectious Disease Control; National Institute for Public Health and the Environment (RIVM); Bilthoven Netherlands
6. Athena Institute; Free University; Amsterdam Netherlands
7. Faculty of Health Sciences; Oslo Metropolitan University; Oslo Norway