Journal Club Summary

Methodology Score: 3/5                 
Usefulness Score: 3/5
Sharp AL, Vinson DR, Alamshaw F, Handler J, Gould MK.
Ann Emerg Med. 2015 Aug 27. pii: S0196-0644(15)00616-2.

Abstract Link

Retrospective study of 31,094 patients investigated for PE, evaluating a traditional D-Dimer of < 500, less than 1000 and an age-adjusted cutoff (age x 10). The age adjusted D-Dimer was associated with a significantly decreased sensitivity (93 vs 98%) but an increased specificity (64% vs 54%) compared to the traditional cutoff. The group agreed that this study does not promote the use of Age-Adjusted D-Dimer, but contributes to a mounting body of literature in favour of its utilization.
By: Dr. Shahbaz Syed
(Presented September 2015)

Epi lesson

Likelihood Ratios:              
For diagnostic tests, LR+ increases the post-test probability of a diagnosis and LR- decreases the post-test probability. LR values generally have this impact:
a) large and conclusive (LR+ >10, LR- <0.1),
b) moderate (LR+ 5 to10, LR- 0.1 to 0.2),
c) small but important (LR+ 2 to 5, LR- 0.2 to 0.5),
d) unimportant (LR+ 1 to 2, LR- 0.5 to 1).
In emergency medicine, we are generally most interested in ruling out serious conditions and look for tests with very high sensitivity and very low LR-.


By: Dr. Ian Stiell