How common is medical journal ghostwriting?

A study in PLoS Medicine concludes that ghost authorship in industry-initiated trials is very common. The authors write that "Ghost authorship, the failure to name, as an author, an individual who has made substantial contributions to an article, may result in lack of accountability."

That's mild. It may be a sign that positive news is being overemphasized and negative news is being squelched. And for journalists who live off the latest tidbit out of a medical journal, and for consumers who rely on news outlets for their health/medical/science news and information, this raises an important new and huge red flag.

The authors looked at 44 industry-sponsored drug trials in Denmark in the 1990s.

"We found evidence of ghost authorship for 33 trials (75%). The prevalence of ghost authorship was increased to 91% (40 of 44 articles) when we included cases where a person qualifying for authorship was acknowledged rather than appearing as an author. In 31 trials, the ghost authors we identified were statisticians. It is likely that we have overlooked some ghost authors, as we had very limited information to identify the possible omission of other individuals who would have qualified as authors."

Why would ghostwriters not be named? The authors write: "This might happen because the study 'looks' more credible if the true authors (for example, company employees or freelance medical writers) are not revealed. This practice might hide competing interests that readers should be aware of, and has therefore been condemned by academics, groups of editors, and some pharmaceutical companies."