Anaphylaxis: Likelihood Ratios

Introduction: None written.

The likelihood ratios of findings for Anaphylaxis are listed below. See the left navigation bar to change the display.

Good Positive and Negative Likelihood Ratios

Finding	+LR	-LR	Comments, Study
Serum Tryptase Duplicate	12.2	0.1	tryptase > 8.23 ng/ml (cutoff of 13 ng/ml decreased sensitivity to 35% without increasing specificity) patients with a clinical allergic rxn < 6 hr in duration - anaphylaxis versus angioedema or urticaria Study: Allergy. 1999 Jun;54(6):602-6. PMID: 10435474
Serial Serum Tryptase	36.5	0.3	increase > 2 mcg/l from 15 min to 60 min post exposure Study: Emerg Med Australas. 2004 Apr;16(2):120-4. PMID: 15239726
Serum Tryptase Duplicate	7.9	0.5	peak tryptase > 9 mcg/l (15 min and 60 min timepoints) Study: Emerg Med Australas. 2004 Apr;16(2):120-4. PMID: 15239726

Good Positive Likelihood Ratio

5.1

0.7

peak tryptase > 12 mcg/l (15 and 60 min timepoints)

Study: Emerg Med Australas. 2004 Apr;16(2):120-4. PMID: 15239726