Objective: To evaluate the precision and construct validity of pediatric Patient-Reported Outcomes Measurement Information System (PROMIS) instruments in a population of juvenile idiopathic arthritis (JIA) patients and parent proxies.
Methods: A convenience sample of JIA patients and parents of JIA patients completed PROMIS instruments for 8 domains: anger, anxiety, depressive symptoms, fatigue, mobility, pain interference, peer relationships, and upper-extremity function. Short form and computerized adaptive test (CAT) scores were derived from item bank responses. Raw scores were translated to standardized T scores with corresponding SEs. Discrimination between inactive versus active disease was evaluated as an indicator of each measure's construct validity. SEs were plotted to evaluate each instrument's relative precision. Patient-parent concordance was assessed using intraclass correlations (ICCs).
Results: A total of 228 patients and 223 parents participated, providing 71-78 responses per domain. Patient- and parent-reported anger, fatigue, mobility, and pain interference scores significantly differed between those with inactive and active disease. Anxiety, depressive symptoms, and peer relationships differed by disease activity levels for parent-report only. Short forms and CATs provided comparable reliability to the full item banks across the full range of each outcome. Patient-parent agreement ranged from ICC 0.3 to 0.8. CATs did not reduce the number of items for any domain compared to the short form.
Conclusion: Precision and discriminatory abilities of PROMIS instruments depend on health domain and report type (self-report versus parent proxy-report) for children with JIA. Varying levels of patient-parent concordance reinforces the importance of considering both perspectives in comprehensive health outcomes assessments.
© 2016, American College of Rheumatology.