Why N of 1 is enough…

Against the mega trial with micro effects

Share with your friends










Submit

Of all the problems regarding large scale clinical trials cataloged by James Penston, the most compelling is the inverse relationship between practical value and trial size.  This could almost be formulated as a law:

The clinical value of a randomized controlled trial is inversely related to its size

Of course, clinical is used in the original sense, meaning at the bedside.

It is a testimony to the effect of propaganda promoting “powerful” clinical trials that this law may sound counter-intuitive when in fact it is so obvious: if it takes 18,000 patients to demonstrate an effect, how relevant or useful is the information likely to be for a clinician dealing with an individual patient?  And there is now some empirical evidence that the phenomenon of conducting, reporting, and inflating trials with “tiny effects” is getting more and more common.

Continue Reading »

The Statistical Alchemy of Meta-Analyses

Share with your friends










Submit

A recent post by Dr. Wes reminded me of the remarkable article Alvan Feinstein wrote in 1995 “Meta-Analysis: Statistical Alchemy for the 21st Century.”  In a few clearly written pages, the founding father of clinical epidemiology brilliantly identifies the wishful thinking underlying meta-analysis and exposes its methodological fallacies.

Continue Reading »