The Earth is an Antioxidant P < 0.05

A week ago, a new study published in Frontiers Physiology titled, “Effectiveness of Grounded Sleeping on Recovery After Intensive Eccentric Muscle Loading” investigated the effects of grounding on recovery in athletes.1 What the Heck Is Grounding? For those who are unaware of what grounding is, the authors give a very brief explanation here in their introduction, Grounding, earthing, or grounded sleeping, is a process in which the athlete becomes grounded via an electrically conducted device. Read More

P-Values Are Tough And S-Values Can Help

The P-value doesn’t have many fans. There are those who don’t understand it, often treating it as a measure it’s not, whether that’s a posterior probability, the probability of getting results due to chance alone, or some other bizarre/incorrect interpretation. [1–3] Then there are those who dislike it for reasons such as believing that the concept is too difficult to understand or because they see it as a noisy statistic that provides something we’re not interested in. Read More

We May Not Understand Control Groups

It’s well known that randomized trials are some of the most efficient ways to make causal inferences and to determine how much something (an intervention) differs from the comparator (some sort of control). Random assignment helps make these goals easier by minimizing selection bias and making the distribution of prognostic factors between groups random (not balanced). [1] Discussions (similar to the one above) praising the efficiency of randomized trials are widespread, however, few of these discussions take a close look at some of the common assumptions that individuals hold regarding randomized trials. Read More

Seductive Surrogates Can Be Deadly

In clinical trials, it’s not always possible to measure hard endpoints like cardiovascular disease events and cancer remission rates. Studies that use clinical outcomes often dichotomize these variables, and as a result, they need to have a large number of participants and be long in duration to detect differences between groups. Again, this type of research is expensive and not always feasible. In many scenarios, a more practical alternative is to focus on intermediate markers. Read More

Problems with the Number Needed to Treat

The number needed to treat (NNT) is a popular statistic used in medicine and its use is even encouraged by groups like Cochrane and CONSORT. Why is it so popular? Most believe that the NNT is more understandable than effect sizes like odds ratios or risk ratios or statistics like the absolute risk reduction. The NNT is also believed to convey more meaningful information. In this blog post, I am going to discuss: Read More