Why is redundant publication a problem?

Duplicate and salami publication: a prevalence study of journal policies

BACKGROUND

Duplicate and salami publication are unethical, but are common practices with substantial consequences for science and society at large. Scientific journals are the 'gatekeepers' of the publication process. We investigated journal policies on duplicate and salami publication.

METHODS

In 2018, we performed a content analysis of policies of journals in the disciplines of 'epidemiology and public health' and 'general and internal medicine'. Journal policies were searched, extracted, coded and cross-checked. The associations of disciplinary categories and journal impact factors with journal policies were examined using Poisson regression models with a robust error variance.

RESULTS

A total of 209 journals, including 122 in epidemiology and public health and 87 in general and internal medicine, were sampled and their policies investigated. Overall, 18% of journals did not have any policies on either practice, 33% only referred to a generic guideline or checklist without explicit mention about either practice, 36% included policies on duplicate publication and only 13% included policies on both duplicate and salami publication. Having explicit journal policies did not differ by journal disciplinary categories (epidemiology and public health vs general and internal medicine) or impact factors. Further analysis of journals with explicit policies found that although duplicate publication is universally discouraged, policies on salami publication are inconsistent and lack specific definitions of inappropriate divisions of papers.

CONCLUSIONS

Gaps exist in journal policies on duplicate and salami publication, characterized by an overall lack of explicit policies, inconsistency and confusion in definitions of bad practices, and lack of clearly defined consequences for non-compliance. Scientific publication and the academic reward systems must evolve to credit good research practice.

Disorganized Systematic Reviews and Meta-analyses: Time to Systematize the Conduct and Publication of These Study Overviews?

The number of meta-analyses published annually has increased more than 20-fold between 1994 (n = 386) and 2014 (n = 8203). In examining how much of this increase in meta-analysis publication has genuinely represented novel contributions to clinical medicine and public health, it became clear that there was an abundance of redundant and disorganized meta-analyses, creating confusion and generating considerable debate. Ironically, meta-analyses, which should prevent redundant research, have become a victim of it. Recently, 17 meta-analyses were published based on the results of only 3 randomized controlled trials that studied the role of transcatheter closure of patent foramen ovale for prevention of cryptogenic stroke. In our search of the published literature, we identified at least 10 topics that were the subject of 10 meta-analyses. In the context of overlapping meta-analyses, one questions what needs to be done to put this "runaway train" back on track. In this review we examine the practice of redundant meta-analyses and the reasons for its disturbing "popularity." The registration of systematic reviews should be mandatory in prospective registries, such as PROSPERO, and the PRISMA checklist should be updated to incorporate new evidence and mandate the reference of previously published reviews and rationale for any new study.