The Crohn's Disease Activity Index or CDAI is a research tool used to quantify the symptoms of patients with

Crohn's disease Crohn's disease is a type of inflammatory bowel disease (IBD) that may affect any segment of the gastrointestinal tract. Symptoms often include abdominal pain, diarrhea, fever, abdominal distension, and weight loss. Complications outside of the ...

. This is of useful importance in research studies done on medications used to treat Crohn's disease; most major studies on newer medications use the CDAI in order to define response or remission of disease. As Crohn's disease is a disease with a variety of symptoms that affect

quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...

, the quantification of symptoms may be of secondary importance to a quantitative assessment of the effect on quality of life. This has been addressed by the Inflammatory Bowel Disease Questionnaire (IBDQ) and other indices of quality of life for patients with Crohn's disease.

Components of the index

The CDAI was developed by WR Best and colleagues from the Midwest Regional Health Center in

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, in 1976. It consists of eight factors, each summed after adjustment with a weighting factor. The components and weighting factors are the following: ^*One point each is added for each set of complications: * the presence of joint pains (

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) or frank

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

* inflammation of the iris or

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* presence of erythema nodosum,

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, or aphthous ulcers * anal fissures,

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e or

abscess An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...

es * other

e *

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

during the previous week. Remission of Crohn's disease is defined as CDAI below 150. Severe disease was defined as a value of greater than 450. Most major research studies on medications in Crohn's disease define response as a fall of the CDAI of greater than 70 points.

Harvey-Bradshaw index

The ''Harvey-Bradshaw index'' was devised in 1980 as a simpler version of the CDAI for data collection purposes. It consists of only clinical parameters: * general well-being (0 = very well, 1 = slightly below average, 2 = poor, 3 = very poor, 4 = terrible) * abdominal pain (0 = none, 1 = mild, 2 = moderate, 3 = severe) * number of liquid stools per day * abdominal mass (0 = none, 1 = dubious, 2 = definite, 3 = tender) * complications, as above, with one point for each. A score of less than 5 is generally considered to represent clinical remission. A Simple Index of Crohn's disease activity has also been developed.

Validation of the CDAI

While the CDAI is considered to be the gold standard for assessing disease activity in Crohn's disease, validation of the index has been varied. A key criticism of the CDAI is that it does not incorporate a subjective assessment of quality of life,

endoscopic An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

factors, or systemic features, such as

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

into its calculation. The CDAI correlated well with

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loss in the bowel in patients with

protein losing enteropathy Protein losing enteropathy (PLE) is a syndrome in which Blood protein, blood proteins are lost excessively via the gastrointestinal tract, gastrointestinal (GI) tract. It may be caused by many different underlying diseases that damage the lining of ...

Inflammatory Bowel Disease Questionnaire

As most symptoms of Crohn's disease broadly affect

, attempts have been made to incorporate physical, social, and emotional performance characteristics into tests for severity of

. The Inflammatory Bowel Disease Questionnaire (IBDQ) was developed to incorporate elements of social, systemic and emotional symptoms, as well as bowel related symptoms into an activity index. In a study of 305 patients in

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

, the IBDQ was found to correlate well with the CDAI in assessing disease activity, but had the added benefit of being a more robust tool for determining the effect of symptoms on perceived quality of life.

References

{{Crohn's disease and ulcerative colitis Crohn's disease