Crohn Disease Activity Index
Quantifies Crohn disease activity using symptoms, laboratory and weight.
When to use
Adults with Crohn disease, to quantify clinical activity and treatment response.
Pearls and pitfalls
- CDAI uses the 7-day stool total and the daily averages of pain and well-being over 7 days.
- Hematocrit has different coefficients for men and women.
- Weight enters only when it is below ideal weight.
- The index is clinical and does not replace endoscopy, imaging or inflammatory markers when indicated.
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Formula
CDAI = 2 × 7-day stools + 35 × mean pain + 49 × mean well-being + 20 × complications + 30 × antidiarrheal + 10 × mass + 6 × (47 − Hct) in men or 6 × (42 − Hct) in women + percentage deviation from ideal weight.
Evidence
Index derived in the National Cooperative Crohn Disease Study to measure disease activity in clinical trials.
References
- Best WR, Becktel JM, Singleton JW, Kern F Jr. Development of a Crohn's disease activity index. National Cooperative Crohn's Disease Study. Gastroenterology. 1976;70(3):439-444. doi:10.1016/S0016-5085(76)80163-1
Frequently asked questions
What is Crohn Disease Activity Index?
Quantifies Crohn disease activity using symptoms, laboratory and weight. Adults with Crohn disease, to quantify clinical activity and treatment response.
How is the result calculated?
CDAI = 2 × 7-day stools + 35 × mean pain + 49 × mean well-being + 20 × complications + 30 × antidiarrheal + 10 × mass + 6 × (47 − Hct) in men or 6 × (42 − Hct) in women + percentage deviation from ideal weight.
How should the result be interpreted?
Index derived in the National Cooperative Crohn Disease Study to measure disease activity in clinical trials.
What are the 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. 1976;70(3):439-444.