Please see here for guidance for authors.
Since July 2010, The BMJ, along with other journals who are members of the International Committee of Medical Journal Editors, has beeing asking authors to use a revised version of its unified disclosure form (see BMJ 2010;341:c3239).
The unified form is intended to make life easier for authors, in that the same form can be completed for several journals, saving authors the trouble of having to provide slightly different information for different journals. Each journal, will, however, integrate the form into its processes in different ways.
A competing interest exists when professional judgment concerning a primary interest (such as patients' welfare or the validity of research) may be influenced by a secondary interest (such as financial gain or personal rivalry). It may arise for the reviewers of an article in The BMJ when they have a financial interest that may influence-probably without their knowing-their interpretation of an article.
We, the editors of The BMJ, believe that to make the best decision on how to deal with a paper we should know about any such competing interests that reviewers may have. We are not aiming at eradicating competing interests - they are almost inevitable. We will not reject opinions simply because you have a competing interest, but we would like to know about it.
We used to ask authors and reviewers about any competing interests, but we have decided to restrict our request to financial interests. This is largely a tactical move. We hope that it will increase the number of people who disclose competing interests. Our experience, supported by some research data, was that people often did not disclose them.
We are restricting ourselves to asking directly about competing financial interests, but you might want to disclose another sort of competing interest that would embarrass you if it became generally known after publication. The following list gives some examples.
If you want to declare such a competing interest then please add it to your statement.
To learn more about the thinking that has led to this policy please read the editorial Beyond conflict of interest.