Clinical Epidemiological Studies for Improving Patient Care in Juvenile Idiopathic Arthritis

Similar to adults, children can also develop arthritis. The most common type of chronic arthritis in children is called juvenile idiopathic arthritis (JIA) and affects roughly 1 in every 1,000 children in the Netherlands. Since the introduction of biological DMARD therapies, reaching inactive disease has become a realistic target for most JIA patients. Still, there is much room for improvement in patient care for JIA. In this thesis, we applied traditional and advanced epidemiological research methods to patient data from the Wilhelmina Children’s Hospital, the global Pharmachild registry and collaborating registries, in order to answer clinically relevant questions for improving patient care in JIA. We described the occurrence and predicting factors of comorbidities, which are common and complicate the approach to treating JIA. We developed and validated for the first time a model for predicting uveitis, that can assist clinicians in determining screening frequencies and drug therapy. We furthermore reported a protective effect of methotrexate therapy on developing JIA-associated uveitis, identified factors that can be used to distinguish JIA from non-inflammatory chronic pain syndrome at the early diagnosis stage, and compared the effects of two common biological drug therapies on patient-reported well-being. In addition, we enrolled patients in two prospective studies, and concluded that home-monitoring using web-based questionnaires is a feasible and much appreciated method of remotely tracking disease activity, and that vaccination against meningococcal disease is safe but elicits a weaker immune response in patients using biological therapy