Background and Objectives: Longitudinal assessment of disease activity is necessary for studies of therapeutic intervention in children with Crohn disease. The Pediatric Crohn Disease Activity Index (PCDAI) was developed a decade ago for such a purpose, but it function has only been examined in a small number of studies with a limited number of patients. The primary objectives of the present study were to develop cut scores reflecting disease activity as determined by physician global assessment (PGA) and to evaluate the responsiveness of the PCDAI to changes in patient condition after therapeutic interventions.
Methods: Data were derived from a prospective database of newly diagnosed children with inflammatory bowel disease established in 2002 at 18 pediatric gastroenterology centers in the United States and Canada. At diagnosis, at 30 days and 3 months after diagnosis, and quarterly thereafter, children (<16 years of age) with Crohn disease had disease assessment performed by PGA and PCDAI. Disease management was provided according to the dictates of the attending gastroenterologist and not by predetermined protocol.
Results: 181 patients had concomitant PGA and PCDAI performed at diagnosis, and 95 of these had similar assessment at short-term follow up. Mean ± SD PCDAI scores for mild, moderate, and severe disease by PGA at diagnosis were 19.5 ± 10.4, 32.2 ± 12.7, and 47.8 ± 14.9, respectively (P < 0.001 for all comparisons). Mean ± SD PCDAI for inactive disease after treatment was 5.2 ± 5.4. Receiver operating characteristic (ROC) curve analysis suggested that: 1) activity of moderate/severe disease was best reflected by a PCDAI of ≥30 points, 2) clinical response (moderate/severe disease improving to mild/inactive) was best reflected by a decrease in PCDAI of ≥12.5 points, and 3) a PCDAI < 10 best reflected inactive disease.
Conclusions: PCDAI scores accurately reflect disease activity as assessed by physician global assessment. A PCDAI score of ≥30 has acceptable sensitivity and specificity to indicate disease of moderate/severe activity. A PCDAI decrease of 12.5 points or greater following therapeutic intervention accurately reflects a clinically significant response. The PCDAI is an appropriate tool for intervention trials in Crohn disease in children.
*Connecticut Children's Medical Center, Hartford, Connecticut; †NorthShore-Long Island Jewish Health System, New Hyde Park, New York; ‡IWK Health Centre, Halifax, Nova Scotia; §Morristown Memorial Hospital, Morristown, New Jersey; ∥Children's Hospital of Eastern Ontario, Ottawa, Ontario; ¶Children's Hospital, Boston, Massachusetts; #7) Medical College of Wisconsin, Milwaukee, Wisconsin; **Riley Hospital for Children, Indianapolis, Indiana; ††Children's Hospital of Michigan, Detroit, Michigan; ‡‡Nemours Children's Clinic, Jacksonville, Florida; §§Duke University, Durham, North Carolina; ∥∥Cleveland Clinic, Cleveland, Ohio; ¶¶St. Louis Children's Hospital, St. Louis, Missouri; ##AI DuPont Hospital for Children, Wilmington, Delaware; ***Floating Hospital for Children, Boston, Massachusetts; †††Children's Medical Center, Dayton, Ohio; ‡‡‡Johns Hopkins Hospital, Baltimore, Maryland; §§§Hospital for Sick Children, Toronto, Ontario
Received September 16, 2004; accepted March 3, 2005.
Address correspondence and reprint requests to Jeffrey Hyams, M.D., Connecticut Children's Medical Center, 282 Washington Street, Hartford, CT (e-mail: email@example.com).