Increased school absence among children with juvenile idiopathic arthritis - a national matched comparison study.

OBJECTIVE This study compares rates of school absence (SA) of all children with juvenile idiopathic arthritis (JIA) attending public Danish schools to peers both before and after JIA diagnosis. Further, we aimed to investigate the role of socioeconomic status (SES) on the possible association. METHODS We performed a register-based matched cohort study. We included all children attending public Danish schools between 2010 and 2019 diagnosed with JIA and compared them to school mates. Rates of differentiated and total SA both before and after JIA diagnosis were compared. In the primary study we included children diagnosed with JIA after starting school, whereas the secondary study only included children diagnosed before starting school. RESULTS We included 716 children with JIA and 3632 matched controls in the primary study and 382 children with JIA and 1910 matched controls in the secondary. Our primary study showed higher rates of sickness SA and total SA from three years before diagnosis and the following five years among children with JIA. After diagnosis, JIA children also had significantly more legal (planned) SA. Children diagnosed with JIA before starting school (secondary study) had significantly more SA (both sickness SA and legal school SA) up to 8th grade. In both studies children of low SES both with and without JIA had highest rates of SA, although no difference in the association between JIA and SA across SES groups were found. CONCLUSION Children with JIA had more sickness and legal absence from school.