Expressions of concern and their uses

The rights and responsibilities of journal editors, when allegations of research misconduct are made, are still evolving. One of the issues that editors must consider is whether and how to communicate with their readership after notice that an allegation of research misconduct has been made about a published article. On receiving such notice, some editors have issued an 'expression of concern' to inform their readers of a potential problem. This article provides an analysis of the 16 expressions of concern that have been issued, how and when they were issued, and what happened next. Although this tool is relatively new, editors should consider it as part of their armament for ensuring the integrity of the research record during the sometimes lengthy period that misconduct investigations can take, and should develop policies regarding its use.