Crohn's Disease Activity Index
Encyclopedia
The Crohn's Disease Activity Index or CDAI is a research tool used to quantify the symptoms of patients with Crohn's disease
. This is of 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
, 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.
, in 1976. The index consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI and weighting factors are the following:
* One point each is added for each set of complications:
Remission
of Crohn's disease is defined as a fall in the CDAI of less than 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.
A Simple Index of Crohn's disease activity has also been developed.
factors, or systemic features, such as fatigue
into its calculation. Interestingly, the CDAI correlated well with protein
loss in the bowel in patients with protein losing enteropathy
.
, attempts have been made to incorporate physical, social, and emotional performance characteristics into tests for severity of Crohn's disease
. 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
, 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.
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
. This is of 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
Remission
Remission may refer to:*Remission , the state of absence of disease activity in patients with a chronic illness, with the possibility of return of disease activity*Remission , the reflection or scattering of light by a material...
of disease. As Crohn's disease is a disease with a variety of symptoms that affect quality of life
Quality of life
The term quality of life is used to evaluate the general well-being of individuals and societies. The term is used in a wide range of contexts, including the fields of international development, healthcare, and politics. Quality of life should not be confused with the concept of standard of...
, 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 IllinoisIllinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, in 1976. The index consists of eight factors, each summed after adjustment with a weighting factor. The components of the CDAI and weighting factors are the following:
| Clinical or laboratory variable | Weighting factor |
|---|---|
| Number of liquid or soft stools Feces Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:... each day for seven days |
x 2 |
| Abdominal pain Abdominal pain Abdominal pain can be one of the symptoms associated with transient disorders or serious disease. Making a definitive diagnosis of the cause of abdominal pain can be difficult, because many diseases can result in this symptom. Abdominal pain is a common problem... (graded from 0-3 on severity) each day for seven days |
x 5 |
| General well being, subjectively assessed from 0 (well) to 4 (terrible) each day for seven days | x 7 |
| Presence of complications* | x 20 |
| Taking Lomitil or opiates for diarrhea | x 30 |
| Presence of an abdominal mass (0 as none, 2 as questionable, 5 as definite) | x 10 |
| Hematocrit Hematocrit The hematocrit or packed cell volume or erythrocyte volume fraction is the percentage of the concentration of red blood cells in blood. It is normally about 45% for men and 40% for women... of <0.47 in men and <0.42 in women |
x 6 |
| Percentage deviation from standard weight | x 1 |
- the presence of joint pains (arthralgiaArthralgiaArthralgia literally means joint pain; it is a symptom of injury, infection, illnesses or an allergic reaction to medication....
) or frank arthritisArthritisArthritis is a form of joint disorder that involves inflammation of one or more joints.... - inflammation of the irisIris (anatomy)The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
or uveitisUveitisUveitis specifically refers to inflammation of the middle layer of the eye, termed the "uvea" but in common usage may refer to any inflammatory process involving the interior of the eye.... - presence of erythema nodosumErythema nodosumErythema nodosum is an inflammation of the fat cells under the skin characterized by tender red nodules or lumps that are usually seen on both shins...
, pyoderma gangrenosumPyoderma gangrenosumPyoderma gangrenosum is a disease that causes tissue to become necrotic, causing deep ulcers that usually occur on the legs. When they occur, they can lead to chronic wounds. Ulcers usually initially look like small bug bites or papules, and they progress to larger ulcers. Though the wounds...
, or aphthous ulcersMouth ulcerA mouth or oral ulcer is an open sore in the mouth, or rarely a break in the mucous membrane or the epithelium on the lips or surrounding the mouth. The types of mouth ulcers are diverse, with a multitude of associated causes including: physical abrasion, acidic fruit, infection, other medical... - anal fissureAnal fissureAn anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on the toilet paper, sometimes in the toilet. If acute they may cause severe periodic pain after defecation but with chronic fissures pain intensity is often less...
s, fistulaFistulaIn medicine, a fistula is an abnormal connection or passageway between two epithelium-lined organs or vessels that normally do not connect. It is generally a disease condition, but a fistula may be surgically created for therapeutic reasons.-Locations:Fistulas can develop in various parts of the...
e or abscessAbscessAn abscess is a collection of pus that has accumulated in a cavity formed by the tissue in which the pus resides due to an infectious process or other foreign materials...
es - other fistulaFistulaIn medicine, a fistula is an abnormal connection or passageway between two epithelium-lined organs or vessels that normally do not connect. It is generally a disease condition, but a fistula may be surgically created for therapeutic reasons.-Locations:Fistulas can develop in various parts of the...
e - feverFeverFever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
during the previous week.
Remission
Remission
Remission may refer to:*Remission , the state of absence of disease activity in patients with a chronic illness, with the possibility of return of disease activity*Remission , the reflection or scattering of light by a material...
of Crohn's disease is defined as a fall in the CDAI of less than 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 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, endoscopicEndoscopy
Endoscopy means looking inside and typically refers to looking inside the body for medical reasons using an endoscope , an instrument used to examine the interior of a hollow organ or cavity of the body. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ...
factors, or systemic features, such as fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...
into its calculation. Interestingly, the CDAI correlated well with protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
loss in the bowel in patients with protein losing enteropathy
Protein losing enteropathy
Protein losing enteropathy refers to any condition of the gastrointestinal tract that results in a net loss of protein from the body.-Presentation:...
.
Inflammatory Bowel Disease Questionnaire
As most symptoms of Crohn's disease broadly affect quality of lifeQuality of life
The term quality of life is used to evaluate the general well-being of individuals and societies. The term is used in a wide range of contexts, including the fields of international development, healthcare, and politics. Quality of life should not be confused with the concept of standard of...
, attempts have been made to incorporate physical, social, and emotional performance characteristics into tests for severity of Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
. 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
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, 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.
External links
- Online CDAI calculator note the addition of a maximum weight deduction of 10%