When to address fatigue in juvenile idiopathic arthritis during clinical visits based on the JAMAR

Objectives Fatigue is a prevalent but overlooked issue among patients with Juvenile Idiopathic Arthritis (JIA) in clinical practice. The internationally widely used Juvenile Arthritis Multidimensional Assessment Report (JAMAR) does not include items on fatigue. We evaluated whether items from its Quality of Life (QoL) section could be used as proxy measurement for fatigue, prompting practitioners to address issues with fatigue during a clinical visit. Methods 105 JIA patients at the Wilhelmina Children's Hospital (WCH) completed the JAMAR and Checklist Individual Strength-8 (CIS-8), a questionnaire with validated cut-off score for severe fatigue in rheumatic conditions. Correlations were inspected to test whether QoL items 3 (difficulty with energy-demanding activities) and 9 (concentration or attention issues) correlated strongest with severe fatigue. With binary logistic regressions and ROC analyses, the proxy's predictive value and cut-off were determined. The proxy was re-used in the EPOCA cohort for comparison. Results The proposed items showed the strongest correlation with severe fatigue (ritem3 = 0.644 and ritem9 = 0.565). Their sum score represented the proxy (range 0-6). The proxy was a significant predictor of severe fatigue controlled for age, sex, and disease activity (P < 0.001). Area Under the Curve was 0.911, sensitivity 90% and specificity 69.6% with cut-off score ≥1. According to the proxy, fatigue should be addressed in 58.1% of WCH patients and in 56.6% of the EPOCA cohort. Conclusion The proxy can be used to estimate whether issues with fatigue should be explored during clinical visits. To quantify fatigue severity levels, we recommend using the CIS-8 or another fatigue questionnaire.