The retraction of scientific papers has increased since the turn of the millennium, and a recent article published in Research Integrity and Peer Review aims to get to the bottom of how widespread the influence of such articles becomes in the literature base, in spite of their retraction. Using a case study, researchers Paul van der Vet and Harm Nijveen studied the extent of citation networks and the impact of retraction on these networks. For example, if a paper is cited in another article to support research conclusions, but is later retracted, to what extent does this pollute the second article, or subsequent articles that cite the second article?
To dig deeper into this phenomenon the team examined the citation network of a retracted Nature paper. They found an expansive citation network of 1626 articles, of which 57 directly cited the retracted paper. The vast majority of these 57 papers did not indicate the retraction of the original article, nor did the authors seem to be aware of it. Another significant finding is that half of these direct citations were reviews. Given the credibility attached to review articles, and their use as sources within the research community, there would appear to be strong potential for cited, retracted articles to impact future research. The researchers also found other papers that cited aspects of the retracted study’s methodology, or used the findings as supporting evidence in their introduction and discussion sections, again raising concerns regarding the potential impact of the retracted paper on the research that directly cites it. Interestingly, the case study did not find any propagation of retracted articles via indirect citations, suggesting stringent citing behaviour among the scientific community.
Due to the inevitable delay between publication and subsequent retraction, there is an unavoidable potential for retracted articles to be cited elsewhere. This is worsened by the current lack of a consistent, coherent system to alert authors if a paper they cite is later retracted. Currently such information is present on the journal’s homepage and on PubMed, but not uniformly on other search engines. The website Retraction Watch is hoping to tackle this with its plans to set up a free electronic database of retractions, as a comprehensive resource for the scientific community.