Th e DISABKIDS project is a European collaboration of clinicians and investigators that received funding from the European Commission in 2001. Over the last four years the DISABKIDS project's aim was to cross-nationally develop a new European health related quality of life (HRQoL) instrument for children and adolescents with a chronic medical condition 1(Box 1). Some of the steps taken during the developmental process of the European DISABKIDS HRQoL instrument for children and adolescents with a chronic medical condition are described in this thesis. Data from the asthma population is a recurring theme in most chapters as the Dutch DISABKIDS centre operated as asthma consultantLEI Universiteit Leiden(Klinisch) epidemiologisch onderzoek bij kindere
