Pain Interference in Juvenile Idiopathic Arthritis.

Objective: Despite treatment advances, pain remains a serious problem for many children with juvenile idiopathic arthritis (JIA). To better understand pain in children with JIA and identify potentially modifiable factors, this study evaluated Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric Pain Interference (PI) and its relationships with other pain measures and demographic, clinical, psychosocial, and functional variables.

Methods: This cross-sectional, observational, multicenter study used descriptive statistics and a mix of bivariate and multivariable analyses to describe PI and characterize relationships with other measures and variables.

Results: Among 355 children with JIA, 27% reported moderate or severe PI and 13.3% reported daily pain. PI correlated with other pain measures. Increasing age, decreasing disease duration, and increasing number of active joints, as well as presence of active disease, steroid treatment, and biologic treatment, were associated with greater PI. All PROMIS psychosocial and functional measures were associated with PI in the expected direction except for PROMIS Pediatric Physical Activity, which showed no association. In multivariable analyses, only PROMIS Fatigue, PROMIS Mobility, and the exploratory interaction of PROMIS Anxiety and disease-modifying antirheumatic drug treatment were significant.

Conclusion: Moderate and severe PI was prevalent in this sample of children with JIA. PI increased with age and indicators of disease activity, but was more strongly associated with increasing fatigue and decreasing mobility. Findings support the use of PI as a short, easily administered multidimensional pain measure as part of routine clinical care. Fatigue, mobility, and disease activity should be assessed further when PI is high.