1. VU University Medical Center; Department of General Practice and Elderly Care Medicine, Amsterdam Public Health Research Institute; PO Box 7057 Amsterdam Netherlands 1007 MB
2. Erasmus Medical Center; Department of General Practice; PO Box 2040 Room Ff303 Rotterdam Netherlands 3000 CA
3. Maison Medical Bel Air; 154 Avenue Bel Air Carpentras France 1084200
4. Erasmus Medical Center - Sophia Children's Hospital; Department of Paediatrics, Paediatric Rheumatology; PO Box 2060 Rotterdam Netherlands 3000 CB