What is salami slicing? Simply put, this involves publishing separate, but similar articles that rely on the same set of data. Researchers may slice the salami to increase their publishing output and drugmakers may view this as a way to promote useful findings for their meds. And anew article in Psychotherapy and Psychosomatics finds that's what occured with Lilly's Cymbalta antidepressant.
The researchers examined 43 pooled analyses and found 88 percent had at least one author who worked for Lilly. They also contend several pooled analyses were based on 'highly' overlapping clinical trials presented safety and efficacy data, but didn't answer unique research questions. And they found six clinical trials had data that was used as part of 20 or more separately published pooled analyses. The upshot: "Such redundant publications add little to scientific understanding and represent a poor use of peer reviewer and editorial resources."
Why pooled analyses? The researchers write that "most research on salami publications has focused on overlapping publications of individual clinical trials, but little attention has been placed on pooled analyses, publications in which data from several clinical trials are pooled into a single, larger dataset. However, pooled analyses also present the potential of salami publications, as similar variables from the same, or highly similar, set of clinical trials could be presented across several pooled analyses."
Here are a few examples they cite:
One study compared Cymbalta safety and efficacy for treating African-Americans and Caucasians, while another study used data from the same underlying clinical trials to compare treatment for Hispanics and Caucasians. In both cases, the authors concluded the racial groups didn't reveal meaningfully different responses to the drug.
Another pooled analysis compared safety outcomes in males and females, and another analysis based on the same underlying patients compared genders in terms of efficacy, with neither analysis finding any notable differences along gender lines.
One pooled analysis eamined cardiovascular effects in depressed patients, while another such analysis reported on the cardiovascular profile of the drug across various conditions. And both concluded that the drug possesses a benign cardiovascular safety profile.
In discussing their findings, the researchers don't argue that the questions examined in the pooled analyses lacked legitimate scientific importance. They also acknowledge that one limitation of their work is the "inappropriateness of salami slicin isn't universally agreed upon."
"However, we believe that publishing similar outcomes from the same dataset of publications on several occasions better serves the curricula vitae of researchers and, potentially, goals of drug marketers, than it does science and patient care," they conclude. "Journal editors, peer reviewers, and researchers should be aware that salami publication wastes valuable resources of editors, reviewers, and journals. Further, salami publications may be more representative of propaganda than of actual contributions to science."
We should also note that, as psychologists, the researchers may advocate therapy before, or instead of, medication, an issue that has been raised before on this site when discussing psychology's views of antidepressants.
Salami thx to David Blaine Flickr Creative Commons