Comparison of Patient-Reported Outcomes Measurement Information System Computerized Adaptive Testing Versus Fixed Short Forms in Juvenile Myositis.

Objective: Patient-Reported Outcomes Measurement Information System (PROMIS) measures can be administered via computerized adaptive testing (CAT) or fixed short forms (FSFs), but the empirical benefits of CAT versus FSFs are unknown in juvenile myositis (JM). The present study was undertaken to assess whether PROMIS CAT is feasible, precise, correlated with FSFs, and less prone to respondent burden and floor/ceiling effects than FSFs in JM.

Methods: Patients 8-17 years of age (self-report and parent proxy) and parents of patients 5-7 years of age (only parent proxy) completed PROMIS fatigue, pain interference, upper extremity function, mobility, anxiety, and depressive symptoms measures. Pearson correlations, paired t-tests, and Cohen's d were calculated between PROMIS CAT and FSFs. McNemar's test assessed floor/ceiling effects between CAT and FSFs. Precision and respondent burden were examined across the T score range.

Results: Data from 67 patient-parent dyads were analyzed. CAT and FSF mean scores did not significantly differ except in parent proxy anxiety and fatigue (effect size 0.23 and 0.19, respectively). CAT had less pronounced floor/ceiling effects at the less symptomatic extreme in all domains except self-report anxiety. Increased item burden and higher SEs were seen in less symptomatic scorers for CAT. Modified stopping rules limiting CAT item administration did not decrease precision.

Conclusion: PROMIS CAT appears to be feasible and correlated with FSFs. CAT had less pronounced floor/ceiling effects, allowing detection of individual differences in less symptomatic patients. Modified stopping rules for CAT may decrease respondent burden. CAT can be considered for long-term follow-up of JM patients.