Researchers analyzing the prevalence of ghostwriting in leading medical journals over more than a decade saw a decline but found inappropriate authorship remained all too common.

Occurrence of articles with honorary or ghost authorship, or both, was 21.0% in 2008, said researchers writing in the BMJ today. By comparison, a similar JAMA review (published in 1998 and analyzing articles from 1996) reported a rate of 29.2%.

The BMJ study was international in scope, including the six general biomedical journals with the highest impact factors in 2008: Annals of Internal Medicine, JAMA, Lancet, Nature Medicine, New England Journal of Medicine, and PLoS Medicine. The highest occurrence of honorary or ghost authorship occurred in original research articles, compared with editorials and review articles.

A total of 630 authors responded to the survey. While there was no significant change in the prevalence of honorary authorship between the 2008 review and the earlier JAMA review (19.3% vs. 17.6%), a decline was seen in the prevalence of ghost authors (11.5% vs. 7.9%).

The researchers, all of whom are current staff members of JAMA, want rates to decrease even further. With more than one out of five articles in high-impact journals showing signs of inappropriate authorship, they called for additional measures by scientific journals, individual authors and academic institutions “to prevent a practice that might lead to loss of public confidence.”

Indeed, results suggest that standards need tightening up, agreed two staffers from the journal Neurology, in an editorial accompanying the BMJ study.

The International Committee of Medical Journal Editors (ICMJE) authorship criteria, which were used as a basis to gauge self-reported outcomes in the BMJ study, frown upon honorary and ghost authoring. The former occurs when individuals who have not contributed to the work or manuscript sufficiently are named, while a ghost author is one who is involved in the work and manuscript preparation but goes unnamed.

More than 600 biomedical journals have signed onto the ICMJE criteria, and scientific journals have taken steps to strengthen their own authorship rules, like requiring that each author report his or her contributions to the published work. However, a secondary analysis in the BMJ study showed that rates of inappropriate authorship did not differ significantly between journals with and without such rules.

Other studies have found the prevalence of honorary authors to be as high as 39%, and ghost authors as high as 11% across a range of journals.

Honorary and ghost authorship, the authors of the BMJ study added, can have negative implications. For instance, promotion and tenure committees may examine a faculty member’s number of publications rather than that faculty member’s substantive contributions to the work.

Likewise, readers of ghostwritten papers “may not appreciate the influence or potential underlying agenda these individuals may have on the reporting of material in the article (such as may occur with ghost authors employed by industry).”