Better guidance is needed for editorial expressions of concern.

On occasion, following the publication of a paper, serious concerns might be raised, either about the study, the author(s), or background processes. When editors-in-chief (EiCs) have sufficient evidence in the case of a serious ethical offense or methodological errors that may invalidate the paper's findings or ethical standing, they can retract the paper rapidly. However, in the interim period between receiving a report and seeking a solution, several weeks, months or even years might pass, and readers need to be alerted to its potential unreliability. In such an instance, the current alertive (but not corrective) document takes the form of an editorial expression of concern (EoC). However, a case might be unresolved for a long time, with an EoC attached to it, so EiCs are encouraged to seek a resolution as promptly as possible because there are academics who might need to cite and/or rely on that paper. Curiously, even though a comprehensive debate is provided by COPE ethics guidelines and ICMJE recommendations, which refer to EoCs, guidance is not entirely clear. This paper makes an attempt to improve guidelines that editors could consider when faced with the dilemma of whether to issue an EoC, or not.