CDAI Calculator

What Is the Crohn Disease Activity Index?

The Crohn Disease Activity Index (CDAI) quantifies inflammatory bowel disease activity from symptoms, physical findings, and laboratory data collected over seven days. It helps track response to therapy and research endpoints. Related tools: CAGE Questionnaire Calculator and Braden Score Calculator.

Score Components

CDAI combines stool frequency, abdominal pain, general well-being, complications, antidiarrheal use, abdominal mass, hematocrit deficit, and weight loss relative to ideal weight. Each domain carries a fixed multiplier reflecting its clinical weight in the original validation study.

$$\text{CDAI} = \sum \text{weighted clinical variables}$$

Interpretation Bands

• Below 150: remission
• 150 to 450: active Crohn disease
• Above 450: severe disease

Clinical Use

Gastroenterologists use CDAI in trials and sometimes in practice to document disease course. It requires reliable patient diaries and consistent examiner assessment of abdominal mass and complications.