Crohn's disease is a chronic inflammatory disease of the alimentary tract and can affect any part of it, from the mouth to the anus. It typically affects the terminal ileum and well -demarcated areas of the large intestine.
Crohn's disease activity index (CDAI) is a measure of the progress or lack of it, in patients suffering from Crohn's disease. It is used for the detection of post-operative recurrence of Crohn's disease. The equation enumerated below, utilizing eight selected variables, is called Crohn's Disease Activity Index.
CDAI = 2x1 + 5x2 + 7x3 + 20x4 + 30x5 + 10x6 + 6x7 + (weight factor) 8
Each number in the above equation is multiplied pertains to certain factors.
These factors range from the number of liquid or soft stool that a patient passes to the hematocrit measure. Fluctuations in the weight are also considered to be serious factors influencing the CDAI. The other factors considered in the index are abdominal pain ratings on a scale from 0 to 3. General well-being is also factored in a scale of 0 to 4.The symptoms or findings related to the disease are given due importance. The number of incidences of administration of the specific drug, Lomotil for diarrhea is also a factor considered in the equation. Abnormal mass of a patient constitutes yet another parameter for calculating the activity index.
Hematocrit is an important measure of both the number and size of red blood corpuscles. The normal count in males is supposed to be 47 whereas females generally have a hematocrit value of 42.
Generally speaking, CDAI scores below 150 indicate a better prognosis than higher scores. Index values of 150 and below are associated with inactive disease, values above that indicate active disease, and values above 450 are seen with extremely severe disease. Crohn's disease activity index may identify patients in remission. However, many researchers use a 'subjective value' of 200 to 250.
CDAI is used to gauge only the progress by comparing the readings from one week to the next and determine if the patient of Crohn's disease is getting better or worse. Patients of the disease have to use the CDAI on a regular basis and view it as a personal gauge to measure progress.