Background:
We evaluated the psychometric performance of the pediatric ulcerative colitis activity index (pucai) in a real-life cohort from the pediatric ibd collaborative research group.
Methods:
Two consecutive visits of 215 children with ulcerative colitis (uc) were included (mean age 11.2 +/- 3.6 years; 112 (52%) males; 63 (29%) newly diagnosed and the others after disease duration of 24 +/- 15.6 months). validity was assessed using several constructs of disease activity. distributional and anchor-based strategies were used to assess the responsiveness of the pucai to change over time following treatment.
Results:
Reflecting feasibility, 97.6% of 770 eligible registry visits had a completed pucai score versus only 47.6% for a contemporaneously collected pediatric crohn's disease activity index (odds ratio = 45.8, 95% confidence interval [ci] 28.6-73.5) obtained for children with crohn's disease accessioned into the same database. the pucai score was significantly higher in patients requiring escalation of medical therapy (45 points [interquartile range, iqr, 30-60]) versus those who did not, (0 points [iqr 0-10]; p < 0.001), and was highly correlated with physician's global assessment of disease activity (r = 0.9, p < 0.001). the best cutoff to differentiate remission from active disease was 10 points (area under receiver operating characteristic curve [auc] 0.94; 95% ci 0.90-0.97). test-retest reliability was excellent (intraclass correlation coefficient = 0.89; 95% ci 0.84-0.92, p < 0.001) as well as responsiveness to change (auc 0.96 [0.92-0.99]; standardized response mean 2.66).
Conclusion:
This study on real-life, prospectively obtained data confirms that the pucai is highly feasible by virtue of the noninvasiveness, valid, and responsive index. the pucai can be used as a primary outcome measure to reflect disease activity in pediatric uc.