While previous research in juvenile idiopathic arthritis (JIA) has identified discrepancy between parent and child perception of disease-related symptoms such as pain, the significance and impact of this disagreement has not been characterized. We examined the extent to which parent-child discordance in JIA symptom ratings are associated with child functional outcomes. Linear regression and mixed effects models were used to test the effects of discrepancy in pain and fatigue ratings on functional outcomes in 65 dyads, consisting of youth with JIA and one parent. Results suggested that children reported increased activity limitations and negative mood when parent and child pain ratings were discrepant, with parent rated child pain much lower. Greater discrepancy in fatigue ratings was also associated with more negative mood, whereas children whose parent rated child fatigue as moderately lower than the child experienced decreased activity limitations relative to dyads who agreed closely on fatigue level. Implications of these results for the quality of life and treatment of children with JIA are discussed.

ObjectivesEvaluate construct validity of Patient-Reported Outcomes Measurement Information System (PROMIS) Paediatric measures of symptoms and functioning against measures of disease activity among youth with juvenile idiopathic arthritis (JIA) or systemic lupus erythematosus (SLE).DesignCross-sectional associations among PROMIS measures and clinical metrics of disease activity were estimated.SettingSeven clinical sites of the Childhood Arthritis and Rheumatology Alliance (CARRA) in the USA.ParticipantsYouth aged 8–17 years enrolled in the CARRA Registry.InterventionPROMIS measures were collected and associations with clinical measures of disease activity estimated, by condition, in bivariate and multivariable analyses with adjustment for sociodemographics, insurance status, medications and disease duration.Main outcome measuresPROMIS Paediatric measures of mobility, physical activity, fatigue, pain interference, family relationships, peer relationships, depressive symptoms, psychological stress, anxiety, and meaning and purpose, and clinical metrics of disease.ResultsAmong 451 youth (average age 13.8 years, 71% female), most (n=393, 87%) had a JIA diagnosis and the remainder (n=58, 13%) had SLE. Among participants with JIA, those with moderate/high compared with low/inactive disease had, on average, worse mobility (multivariable regression coefficient and 95% CIs) (−7.40; −9.30 to –5.50), fatigue (3.22; 1.02 to 5.42), pain interference (4.76; 3.04 to 6.48), peer relationships (−2.58; −4.52 to –1.64), depressive symptoms (3.00; 0.96 to 5.04), anxiety (2.48; 0.40 to 4.56) and psychological stress (2.52; 0.68 to 4.36). For SLE, youth with active versus inactive disease had on average worse mobility (−5.07; −10.15 to 0.01) but PROMIS Paediatric measures did not discriminate participants with active and inactive disease in adjusted analyses.ConclusionsSeven PROMIS Paediatric measures discriminated between active and inactive disease in youth with JIA. Results advance the usefulness of PROMIS for understanding well-being and improving interventions for youth with JIA, but larger studies are needed to determine utility in SLE cohorts.Trial registration numberNational Institute of Arthritis and Musculoskeletal and Skin Diseases (U19AR069522).