Journal Club Summary
Methodology Score: 3/5
Usefulness Score: 2/5
Moler FW, Silverstein FS, Holubkov R, et al.
N Engl J Med. 2015 May 14;372(20):1898-908.
This prospective, multi-center RCT found no significant difference in functional outcomes between hypo- and normo-thermic management following out of hospital arrest, although a clinical difference of 7.3% (favouring hypothermia) was observed and there was no significant difference in safety outcomes. Although the group feels that this supports therapeutic hypothermia, it was agreed that the study was vastly underpowered to achieve significance for important clinical outcomes and further studies would be welcomed.
By: Dr. Christopher Mong
(Presented September 2015)
Epi lesson:
Minimal Clinically Important Difference in Clinical Trials
The sample size of a clinical trial must be adequately powered to show a minimal clinically important difference (MCID) between the intervention and control arms. MCID is the absolute difference in outcome proportions that would have to be shown by the study intervention for clinicians to accept the new treatment as better. In an effort to keep sample size low, investigators sometimes estimate an MCID much larger than is reasonable or use an outcome that is not the most important, e.g. 4-hour survival rather than survival to discharge.
By: Dr. Ian Stiell
