Journal Club Summary

Methodology: 4/5
Usefulness: 3.5/5

Wang HE, et al. JAMA. 2018 Aug 28;320(8):769-778.

Editorial: Pragmatic Airway Management in Out-of-Hospital Cardiac Arrest.

Question and Methods: This multicenter pragmatic cluster-crossover randomized trial compared initial advanced airway strategy effectiveness between laryngeal tube (LT) and endotracheal intubation (ETI) in adults with OHCA.

Findings: The LT group had higher 72-hour survival (18.3%) compared to ETI (15.4%; P=.04), and higher initial airway success rates (LT = 90.3%; ETI = 51.6%).

Limitations: Overall low ETI first-attempt success rate, many patients did not receive their randomized intervention, and other important interventions impacting survival were not balanced between groups.

Interpretation: Our EMS colleagues should use non-ETI advanced airway devices to reduce time off the chest, increase initial airway success, and prevent delays in transfer.

By: Dr. Leo Carroll

Epi Lesson

Multiple Testing: How are Interim Analyses Conducted 

Using a p-value of 0.05 implies that you have a 1 in 20 chance of having a type I error (i.e. identifying a favourable treatment when in fact there is no real difference). This is a potential problem with interim analyses or multiple secondary outcomes. This should be controlled for a-priori with stopping rules and stricter definitions of significance, such that the total, after adjusting for multiple testing is kept at 0.05. The Obrien-Fleming method is one which allocates a small amount of error to the first tests (i.e. 0.0005, 0.0013 and 0.045) for interim analyses.  This gives a final assessment which is similar to a value people are used to (i.e. 0.045 vs the usual 0.05) for the final test. The Bonferroni correction allocates an equal amount to each test (more conservative estimate). Other corrective measures are possible, but they should be stated a-priori and not yield a chance of a type I error of greater than 0.05.
By: Dr. Jeff Perry

Hans Rosenberg
Dr. Rosenberg is an emergency physician at the Ottawa Hospital, assistant professor at the University of Ottawa, and Director of the Digital Scholarship and Knowledge Dissemination Program.