The definition of the Effect Size in clinical research is imperative because the required sample size to detect an effect of an intervention may vary.  The sample size is dependent on the expected outcome that is assumed previously, and the variability of the sample. Therefore, compelling research must describe the Effect Size accurately.
We performed a search in the European Journal of Anaesthesiology (EJA), backward from December 2017 to August 2012, and we included 100 human randomized clinical trials. We searched information about critical elements, such as the estimated Standard Deviation, Effect Size, Missing Data and Confidence Interval.
The findings showed that EJA trials are still leaving out relevant information about the methodology concerning its content. The authors of the human clinical trials described their methods in a varied pattern. The adequate statistical design of clinical research should allow power to interpret the data accurately with minimal interference of bias and statistical flaws.

05 / Effect size in anaesthesia research