CrossMark

We’re updating our article webpages and moving them to a new system. Because of this, on certain journals CrossMark may only be available from the article PDF.

CrossMark is a multi-publisher initiative by the CrossRef Organisation to provide a standard way for readers to locate the authoritative version of a document. By applying the CrossMark logo, BMJ is committed to maintaining the content it publishes and to alerting readers to changes if and when they occur. Clicking on the CrossMark logo will provide the current status of a document and may also provide additional publication record information about the document.

Details of our correction and retraction policies can be found here.