Medical Diagnostics & Clinical Scoring

Crohn's Disease Activity Index (CDAI)

Calculate the CDAI score to quantify the current severity of Crohn's disease symptoms and evaluate response to medical therapy.

Number of liquid or very soft stools (total for 7 days)

Abdominal pain (sum for 7 days: 0=none, 1=mild, 2=mod, 3=severe)

General well-being (sum for 7 days: 0=well, 1=slight under par, 2=poor, 3=very poor, 4=terrible)

Number of complications (Arthritis, Iritis, Erythema nodosum, Anal fissure, Fistula, Fever)

Taking Lomotil or Opiates for diarrhea (0=no, 1=yes)

Abdominal mass (0=none, 2=questionable, 5=definite)

Hematocrit (%)

Weight Deviation (%)

CDAI Score

195.0

Disease StateMild-Moderate (150-300)

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CDAI Overview

The Crohn's Disease Activity Index (CDAI) is the fundamental clinical and research instrument used to quantify the symptoms and severity of Crohn's disease. Historically, it has been the gold standard for defining remission and assessing the efficacy of new biological and medical treatments in clinical trials.

The Complexity of Crohn's Assessment

Crohn's disease is characterized by a wide variety of systemic and gastrointestinal symptoms that fluctuate significantly. The CDAI captures this complexity by aggregating data over a 7-day period to account for day-to-day variability.

Clinical Interpretation

The CDAI assigns mathematical weights to eight variables, resulting in a single composite score:

< 150: Clinical Remission
150 - 219: Mild disease activity
220 - 450: Moderate-to-severe disease activity
> 450: Severe to fulminant disease activity

Score = Sum of 8 weighted clinical and laboratory factors

Frequently Asked Questions

Symptoms of Crohn's disease, such as abdominal pain and stool frequency, can fluctuate dramatically from day to day. A 7-day average provides a more stable, realistic, and accurate representation of the patient's actual disease burden.

Rarely. Because it requires a 7-day diary, hematocrit lab values, and complex weighting calculations, it is heavily favored in clinical trials rather than standard bedside practice. Clinicians often use the Harvey-Bradshaw Index for routine visits.

In most clinical trials, a decrease in the CDAI score of 70 to 100 points from baseline is defined as a 'clinical response,' indicating the patient is benefiting from the therapy.

Crohn's Disease Activity Index (CDAI)

CDAI Overview

The Complexity of Crohn's Assessment

Clinical Interpretation

Frequently Asked Questions

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