Assessing activity of pediatric Crohn's disease: which index to use?

BACKGROUND & AIMS: The Pediatric Crohn's Disease Activity Index (PCDAI) is a multi-item measure that, in contrast to the adult-derived CDAI, includes linear growth and places less emphasis on subjectively reported symptoms but more on laboratory parameters of intestinal inflammation. This study compared the feasibility, validity, and responsiveness of PCDAI vs. CDAI in the assessment of Crohn's disease activity among pediatric patients.

METHODS: Eighty-one children and adolescents with Crohn's disease were studied. A gastroenterologist provided a categorical global assessment of disease activity as quiescent, mild, moderate, or severe after interview and physical examination. CDAI and PCDAI scores were calculated by an independent appraiser.

RESULTS: Mean values within each category for CDAI and PCDAI differed significantly between strata. PCDAI values were quiescent, 6.8 +/- 6. 6; mild, 18.7 +/- 7.3; moderate, 38.5 +/- 12.9; and severe, 54.2 +/- 14.0. CDAI values were quiescent, 23.5 +/- 53.6; mild, 96.0 +/- 60. 7; moderate, 184.5 +/- 97.0; and severe, 284.4 +/- 85.8. Individual scores showed less overlap between strata for PCDAI than for CDAI. PCDAI showed better correlation with serum orosomucoid and platelet count, laboratory parameters of inflammation not included in either index.

CONCLUSIONS: Both PCDAI and CDAI reflect disease activity in pediatric Crohn's disease. PCDAI is better at discriminating between levels of disease activity.