Interpreting Patient-Reported Outcome Scores: Pediatric Inflammatory Bowel Disease as a Use Case

Objective: To demonstrate how to interpret Patient-Reported Outcomes Measurement Information System (PROMIS) pediatric patient-reported outcome measure (PROM) scores for patients with pediatric inflammatory bowel disease (IBD). Methods: Using data from a prospective cohort study of patients ages 8 to 23 years with IBD (n = 1049), we established disease-specific percentiles and computed the minimal clinically important difference (MCID) change score for 6 pediatric PROMs. We applied these results, general population percentiles, and the reliable change index to interpret PROM scores in a clinical trial sample of patients ages 8 to 20 years with IBD (n = 294) in which PROMIS PROMs were obtained at baseline and 3 months later. Results: Application of general population percentiles showed that the clinical trial sample at baseline had moderately worse self-reported health than the general population (22% of patients at or above the 95th percentile on Fatigue; 21% on Pain Interference). IBD-specific percentiles showed that the sample was somewhat worse than the reference IBD sample (8% of patients at or above the 95th percentile on Fatigue; 11% on Pain Interference). Application of the MCID threshold indicated that among the subgroup of patients that improved by 15 or more on the short Pediatric Crohn's Disease Activity Index (n = 38), 45% also improved on IBD Symptoms, 47% for Fatigue, and 65% for Pain Interference. Conclusion: This study established IBD-specific percentiles for 6 pediatric PROMIS measures and demonstrated the application of percentiles and other methods for interpreting PROM scores.