Journal Club Summary
Methodology Score: 4 /5
Usefulness Score: 3.5/5
Wang Y, Johnston SC, Wang Y.
N Engl J Med. 2013 Oct 3;369(14):1376-7.
This multicenter randomized-control trial of 5,100 patients with TIA/minor stroke treated within 24 hours found clopidogrel and aspirin was superior to aspirin alone for secondary prevention of stroke within 90 days (ARR 3.5%, HR 0.68, 95% CI 0.57 – 0.81,p <0.001), without increasing the risk of significant hemorrhage (0.3% in both groups.) JC attendees appreciated the strong methodology, with successful and appropriately stratified randomization and an acceptable loss to follow-up. However, the generalizability to our patient population was questioned as other secondary stroke prevention practices differ in China.
By: Dr. Layli Sanaee
(Presented January 2014)
Epi lesson: Verifying the power of an RCT
The power of a study is defined as “the ability of a study to detect an effect or association if one really exists in a wider population.” Two key questions in determining whether an RCT is adequately powered are: 1) was the sample size detailed for the primary outcome? 2) Is the effect size consistent with the minimally clinically important difference (MCID) used in the sample size calculation?
By: Dr. Lisa Calder