August 2, 2014

When in doubt, randomise

The Cochrane Collaboration, the massive global conspiracy to summarise and make available the results of clinical trials, has developed ‘Plain Language Summaries‘ to make the results easier to understand (they hope).

There’s nothing terribly noticeable about a plain-language initiative; they happen all the time.  What is unusual is that the Cochrane Collaboration tested the plain-language summaries in a randomised comparison to the old format. The abstract of their research paper (not, alas, itself a plain-language summary) says

With the new PLS, more participants understood the benefits and harms and quality of evidence (53% vs. 18%, P < 0.001); more answered each of the five questions correctly (P ≤ 0.001 for four questions); and they answered more questions correctly, median 3 (interquartile range [IQR]: 1–4) vs. 1 (IQR: 0–1), P < 0.001). Better understanding was independent of education level. More participants found information in the new PLS reliable, easy to find, easy to understand, and presented in a way that helped make decisions. Overall, participants preferred the new PLS.

That is, it worked. More importantly, they know it worked.


Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »