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