Journal Club Summary

Methodology Score: 3/5     
Usefulness Score: 2/5
Reichlin T, Twerenbold R, Wildi K, et al.
CMAJ May 19, 2015 187:E243E252;
This multicenter study aiming to prospectively validate a 1 hour algorithm using a high sensitivity cardiac troponin assay classified 59.5% patients in the Rule Out group (30 day mortality was 0%), 16.4% Rule-In (30 day mortality 1.6%) and 24.1 % of patients in the Observational Group (30 day Mortality 1.9%). Limitations of this study included selection bias, incorporation bias and loss to follow-up bias. JC attendees agreed that further studies are warranted prior to applying this algorithm prospectively for clinical deci­sion-making in the ED. 
By: Dr. Ayesha Zia
(Presented Jun 2015)

Epi lesson:  Incorporation bias

It is important when critically appraising studies evaluating a diagnostic technique to closely examine how the outcome was assessed. If the outcome assessment includes the results of the diagnostic test being studied, this is incorporation bias. This can lead to an overestimation of the accuracy of the test. Far preferable is to keep the outcome assessors blinded to the results of the test being evaluated.  
By: Dr. Lisa Calder