Ulcerative Colitis Disease Activity Index (UCDAI)

This Is a Measurement that Is Often Used In Clinical Trials For IBD

Microbiologist Tatiana Travis
Research is a key component in the future of developing a better understanding of the causes and treatments for ulcerative colitis. Image © CDC / Melissa Dankel

Research is an important part of developing new treatments for every disease, including inflammatory bowel disease (IBD). Research often means testing new drug formulations in a small group of patients, in order to determine if it should be tested on a large group, or if the idea should be reformulated or abandoned altogether. There are laws and protocols surrounding the testing of new drugs in patients -- it's not something that is done lightly.

Often, the drug has been tested first in computer models, and then on animals (usually rats or mice). 

How Do Researchers Know If A Treatment Is Working?

In order to determine if a treatment for IBD is effective, scientists often use a specialized scale to measure disease activity in individual patients. Disease activity might include such signs as pain, how many times a person has gone to the bathroom in a day, or even inflammation in the colon that is found when a doctor completes a colonoscopy. In some cases, extra-intestinal markers of disease, like skin, eye, or joint problems, could also be included.

What this does is give the researchers a common language to talk about how each patient is doing while receiving the treatment being tested. These scores may or may not be used by gastroenterologists in clinical practice. Most of the time, they are not, because it doesn't really achieve anything: you wouldn't compare a patient's score against another patient's score, so the result would not be very helpful.

Additionally, it might be too difficult and time-consuming to do the scoring for all patients, especially when there's no real gain to doing it.

The Ulcerative Colitis Disease Activity Index (UCDAI)

For ulcerative colitis, there are several different scoring scales that are used for research. One that is used fairly often is called the Ulcerative Colitis Disease Activity Index (UCDAI).

It goes by other names, and could also be called the Sutherland Index or the Modified Ulcerative Colitis Disease Activity Index. The UCDAI was developed in 1987 by Sutherland, et al.

The UCDAI is a series of qualifiers about the symptoms of ulcerative colitis including stool frequency, rectal bleeding, the appearance of the lining of the colon, and a physician rating of disease activity. Each of these items is given a number from 0 to 3, with 3 being the highest rating for disease activity.

For the purpose of clinical trials, remission is often defined as a UCDAI score of 1 or less, and improvement is a reduction of 3 or more points from the score at the beginning of the trial.

The Bottom Line

The UCDAI, or any other disease activity scale, cannot tell a person whether or not he or she has ulcerative colitis. It is a tool that is used by researchers, often during the course of clinical trials to study the effects of a new medication. Many gastroenterologists don't use this scale, so it isn't something that you should expect to be part of your standard assessment.


Sutherland LR, Martin F, Greer S, et al. "5-Aminosalicylic acid enema in the treatment of distal ulcerative colitis, proctosigmoiditis, and proctitis." Gastroenterology 1987;92:1894–1898. 5 Oct 2010.

Also Known As: Sutherland Index, Modified Ulcerative Colitis Disease Activity Index

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