Crohn's disease activity index (CDAI)

Patient reported stool pattern

Average number of liquid or soft stools per day over seven days (14 points per stool)

Using diphenoxylate or loperimide for diarrhea (30 points)
Average abdominal pain rating over seven days

None (0 points)

Mild pain (35 points)

Moderate pain (70 points)

Severe pain (105 points)
General well being each day over seven days

Well (0 points)

Slightly below average (49 points)

Poor (98 points)

Very poor (147 points)

Terrible (196 points)

Arthritis or arthralgia (20 points)

Iritis or uveitis (20 points)

Erythema nodosum, pyoderma gangrenosum or aphthous stomatitis (20 points)

Anal fissure, fistula or abcess (20 points)

Other fistula (20 points)

Temperature over 100 degrees F (37.8 degrees C) in the last week (20 points)
Finding of an abdominal mass

No mass (0 points)

Possible mass (20 points)

Definite mass (50 points)
Anemia and weight change

Absolute deviation of hematocrit from 47% in males or 42% in females (6 points per percent deviation)

Percentage deviation from standard weight (1 point for each percent deviation)

Total Criteria Point Count:


CDAI Interpretation

0 to 149 points: Asymptomatic remission
150 to 220 points: Mildly to moderately active Crohn's disease
221 to 450 points: Moderately to severely active Crohn's disease
451 to 1100 points: Severely active to fulminant disease

  • Patients requiring steroids to remain asymptomatic are not considered to be in remission but are referred to as being "steroid dependent."
  • Absolute deviation of hematocrit is simply the difference in hematocrit from standard. A male patient with a hematocrit of 40% has an absolute deviation of 7.
  • Percent deviation from standard weight is (1 - weight/standard weight) * 100, thus positive percent deviation represents weight loss, adding points to the CDAI.

  1. Best WR. Predicting the Crohn's disease activity index from the Harvey-Bradshaw Index. Inflamm Bowel Dis. 2006 Apr;12(4):304-10. PubMed ID: 16633052 PubMed Logo
  2. 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 Mar;70(3):439-44. PubMed ID: 1248701 PubMed Logo



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