Clinical features

Ask patients about ^c

• their general well-being in the last 24 hours
• any abdominal pain in the last 24 hours
• the number of liquid stools per day

• an abdominal mass
• any systemic complications 
  • arthralgia
  • uveitis
  • erythema nodosum, pyoderma gangrenosum
  • aphthous ulcers
  • anal fissure
  • new fistula
  • abscess

• Use the following index as an objective measure of relapse. ^c
• It correlates with the Crohn's disease activity index (widely used to monitor disease activity in studies) ^b but is simpler to use. ^c

A disease activity index can be used to monitor relapse and remission in Crohn's disease

Harvey-Bradshaw index c	score
general well-being in the last 24 hours	0 = very well, 1 = slightly below par, 2 = poor, 3 = very poor, 4 = terrible
abdominal pain in the last 24 hours	0 = none, 1 = mild, 2 = moderate, 3 = severe
number of liquid stools per day	1 point per episode
abdominal mass	0 = none, 1 = dubious, 2 = definite, 3 = definite and tender
systemic complications: arthralgia, uveitis, erythema nodosum, aphthous ulcers, pyoderma gangrenosum, anal fissure, new fistula, abscess	score 1 per item

The Harvey-Bradshaw index helps diagnose and exclude relapse in Crohn's disease

Patient	Target Disorder and Reference Standard	Diagnostic Test	LR+ (95% CI)	Post-test Probability
Crohn's disease c (pre-test probability: 32%)	relapse (CDAI index > 150)	≥ 7	38 (5.3 to 270)	95%
		4 to 6	3.0 (1.6 to 5.6)	59%
		≤ 3	0.034 (0.0048 to 0.23)	1.6%