Arnstad ED, Glerup M, Rypdal V, et al. - In the present study, the researchers sought to investigate fatigue in young adults with juvenile idiopathic arthritis (JIA) 18 years after disease onset and to compare with controls. In a population-based prospective cohort study, children with JIA who were diagnosed between 1997 and 2000 in geographically defined areas of Norway, Sweden, Denmark, and Finland were followed for 18 years. The current study included 377 of the participants who completed the Fatigue Severity Scale, 26% of whom reported severe fatigue vs 12% among controls. Fatigue is a common symptom in young adults with JIA, with a higher fatigue burden among participants who have poor sleep, pain, self-reported health problems, active disease, or use of disease-modifying anti-rheumatic drugs/biologics. Participants who do not face these challenges achieve results comparable to controls. At the 18-year follow-up, patient- and physician-reported variables at baseline and throughout the disease, such as female sex, diagnostic delay of ≥6 months at baseline, pain, self-reported poor health, active disease, and previous/ongoing use of DMARDs/biologics at 8 years course, predicted fatigue.