Definition: When doing research to study the effects of treatments for inflammatory bowel disease (IBD), scientists need an objective way to determine an individual's disease activity. One way of doing this is through the Crohn's Disease Activity Index (CDAI), which was developed by Best, et al in 1976. The CDAI is a series of questions that is tailored to the symptoms of Crohn's disease. Once answered, the questions lead to a "score" that helps researchers better gauge one person's disease activity, and compare it to others or to a group. Often the CDAI is given at the start of a research study, at periodic points throughout the study, and at the conclusion of the study. This helps determine if the treatment being studied is ameliorating the symptoms of Crohn's disease or even inducing remission.
The CDAI is not a diagnostic tool; it can not tell a person if they have Crohn's disease. Rather, it is a scoring tool used primarily in research. A pediatric version (the PCDAI) was created in 1991.
Sources:
Best WR, Becktel JM, Singleton JW, Kern F Jr. "Development of a Crohn's disease activity index. National Cooperative Crohn's Disease Study." Gastroenterology Mar 1976;70: 439–444. Sept 14 2010.
Hyams JS, Ferry GD, Mandel FS, Gryboski JD, et al. "Development and validation of a pediatric Crohn's disease activity index." J Pediatr Gastroenterol Nutr May 1991;12: 439-447. Sept 14 2010.
