I have written more than once before about how the commonly heard statistic “50% of all clinical trials are not published” is nonsense. It is a zombie statistic: no matter how many times you try to kill it, it just keeps on coming. And now it turns out its supporters are becoming increasingly dishonest in their attempts to defend it.
The zombie statistic appeared again in the last few days on the Pharmafile website. This was presented as being news, but in fact it described a report that contributed very little new data, and mainly described a publication from last December. The publication, needless to say, did not show that only 50% of clinical trials are published, but if you read it really carelessly, are determined to believe that only 50% of clinical trials are published, and don’t care too much about what the study actually showed, then you might interpret it as meaning that.
What I find really disappointing here, however, is not just that the same old flawed statistic is being rehashed, but that Pharmafile seem determined to resist any attempts at debunking. Jackie Marchington wrote a nice explanation of why the “50% of trials are unpublished” statistic was nonsense, and posted it as a comment to the Pharmafile article.
Sadly, the comment didn’t last long before it was deleted with no explanation. Jackie posted a further comment to ask what had happened to the first one, which was also deleted.
Deleting comments from websites when they disagree with you is a sure sign of a weak argument and intellectual dishonesty. The “50% of clinical trials are unpublished” brigade are surely losing the argument if deleting critical comments is the best they can do.
If you want to read what Jackie had to say, happily she had the foresight to post her comment here as well.