Journal Club Summary

Methodology Score: 5/5                 
Usefulness Score:  3/5
Aufderheide TP, Nichol G, Rae TD, et al.
N Engl J Med. 2011 Sep 1;365(9):798-806
This large effectiveness trial sought to test whether standard CPR with an Impedance Threshold Device (ITD) improves survivor function (Rankin score <=3) for adults suffering out of hospital cardiac arrest. Given the strong methodology and results that did not demonstrate a survival advantage, the group agreed with the AHA recommendation that ITDs no longer be used in pre-hospital cardiac arrests.
By: Dr. Michael O’Brien
(Presented November 2015)

Epi lesson:

Modified Intention-to-treat (M-ITT) Analyses
Intention-to-treat (ITT) analyses are widely recommended as the preferred approach to the analysis of most clinical trials. The basic intention-to-treat principle is that participants in trials should be analysed in the groups to which they were randomized, regardless of whether they received or adhered to the allocated intervention, crossed over to other treatments, or were withdrawn from the study. Post-randomization exclusions may be acceptable when patients are inappropriately randomized into a clinical trial or when pre-randomization information on patients’ eligibility status is not available at the time of randomization. Such an approach is known as “modified intention-to-treat” analysis and must be pre-specified in the protocol. M-ITT is most likely to be seen in RCTs of critical situations, e.g. cardiac arrest. 


By: Dr. Ian Stiell