Crohn's Disease Activity Index

Crohn's Disease Activity Index (CDAI) is a research tool used to quantify the symptoms of patients with Crohn's disease. It was developed in the 1970s by Dr. William Best and his colleagues to provide a standardized measure of disease activity and to track changes over time.

Overview

The CDAI is a composite score that includes eight variables: the number of liquid or very soft stools, the severity of abdominal pain, general well-being, the presence of extraintestinal symptoms, the need for anti-diarrheal medication, the presence of abdominal mass, hematocrit levels, and deviations from ideal weight. Each variable is assigned a weighted score, which are then summed to give a total score. A higher score indicates more severe disease activity.

Calculation

The CDAI score is calculated using the following formula:

CDAI = (2 x number of liquid or very soft stools) + (5 x abdominal pain score) + (7 x general well-being score) + (20 x presence of extraintestinal symptoms) + (10 x use of anti-diarrheal medication) + (30 x presence of abdominal mass) + (6 x (ideal hematocrit - actual hematocrit)) + (1 x (ideal weight - actual weight))

Interpretation

A CDAI score of less than 150 is considered remission, a score of 150-220 indicates mild disease, a score of 220-450 indicates moderate disease, and a score of more than 450 indicates severe disease.

Limitations

While the CDAI is widely used in clinical trials and research, it has several limitations. It is subjective, as it relies on patient-reported symptoms, and it may not accurately reflect the severity of inflammation or damage in the intestines. Furthermore, it does not include some important aspects of the disease, such as the impact on quality of life or the presence of fistulas or abscesses.

See also

• Crohn's disease
• Inflammatory bowel disease
• Ulcerative colitis