Mylène Jansen

Promotor: Prof. dr. F.P.J.G. Lafeber Copromotoren: Dr. S.C. Mastbergen Dr. R.J.H. Custers The research described in this thesis was financially supported by the Dutch Arthritis Society (ReumaNederland), the Netherlands Organisation for Health Research and Development (ZonMW), the Foundation for Research in Rheumatology (FOREUM), and Vrienden UMC Utrecht & Wilhelmina Kinderziekenhuis.