Allan et al developed a clinical index for evaluating symptoms in patients with perianal Crohn's disease. This can be used to monitor disease activity over time or to evaluate the impact of different interventions. The study was done the General Hospital in Birmingham, England.



(1) Patients completed a questionnaire, so no interobserver variation was introduced..

(2) Initially the symptoms were measured for 5 sequential days, but the findings were similar so that symptoms were only queried for the day of completion.

(3) Each parameter was given equal weight.


Initial Parameters for Anal Disease Activity Index


Symptoms related to tissue tension or inflammation:

(1) continuous, spontaneous perianal pain

(2) perianal itching


Symptoms related to sphincter control or disorder:

(3) pain during defecation

(4) anal leakage


Inhibition of normal activity due to perianal discomfort:

(5) locomotion

(6) social activities (visiting friends, entertainment, sport recreation)

(7) sexual activity


Final Parameters for Index


After initial evaluation, 3 parameters were found to have a good discriminant value and to provide a good index of response to treatment:

(1) continuous, spontaneous perianal pain

(3) pain during defecation

(5) inhibition of locomotion due to pain


Scoring of Index


Each finding was graded on a linear analog scale from 0 (none) to 10 (extreme).


average score =

= SUM(parameters measured) / (number of parameters measured)


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