Competing interests (COPE Guideline, pp 5 - 6)
Ensure you declare all potential competing, or conflicting, interests. If you are unsure about a potential competing interest that may prevent you from reviewing, do raise this. Competing interests may be personal, financial, intellectual, professional, political or religious in nature. If you are currently employed at the same institution as any of the authors or have been recent (eg, within the past 3 years) mentors, mentees, close collaborators or joint grant holders, you should not agree to review. In addition, you should not agree to review a manuscript just to gain sight of it with no intention of submitting a review, or agree to review a manuscript that is very similar to one you have in preparation or under consideration at another journal.
Bias and competing interests
It is important to remain unbiased by considerations related to the nationality, religious or political beliefs, gender or other characteristics of the authors, origins of a manuscript or by commercial considerations. If you discover a competing interest that might prevent you from providing a fair and unbiased review, notify the journal and seek advice (eg, see COPE Case 15-05: Reviewer requests to be added as an author after publication) (https://cope.onl/case-author). While waiting for a response, refrain from looking at the manuscript and associated material in case the request to review is rescinded. Similarly, notify the journal as soon as possible if you find you do not have the necessary expertise to assess the relevant aspects of a manuscript so as not to unduly delay the review process. In the case of double blind review, if you suspect the identity of the author(s) notify the journal if this knowledge raises any potential competing or conflict of interest.