1. Department of Anaesthesiology; Amphia Ziekenhuis; Breda; The Netherlands
2. Department of General Practice; Erasmus Medical Center; Rotterdam; The Netherlands
3. Diakonessen Hospital; Zeist; The Netherlands
4. Pfizer bv; Capelle a/d IJssel; The Netherlands
5. Mapi Values; Lyon; France
6. Department of Anaesthesiology Pain treatment centre; Erasmus Medical Center; Rotterdam; The Netherlands