AbstractIn this editorial, I would like to share some thoughts about clinical studies, including value and limitations using as an example a recently published randomized clinical trial. Randomized and non‐randomized clinical trials, epidemiologic studies, and registries guide our clinical practice. They are good but not perfect. Why is this the case? One of the answers is that they provide mean values for outcomes, and mean values do not explain the clinical outcomes of the outliers. A good illustrative example is survival after myocardial infarction. The data that are provided are usually average data, but these data may not reflect the same outcome in patients with little myocardial ischemia and good ventricular function compared to those with poor ventricular function and a large amount of myocardium in jeopardy due to myocardial ischemia. Copyright © 2009 Wiley Periodicals, Inc.