The Cochrane Metabolic and Endocrine Disorders Group withdrew this review as of Issue 7, 2015 because the involvement of two authors (C Hemmingsen and SS Lund) being employed in pharmaceutical companies. The authors of the review and the Cochrane Metabolic and Endocrine Disorders Group did not find that this was a breach of the rules of the Cochrane Collaboration at the time when it was published. However, after the publication of the review, the Cochrane Collaboration requested withdrawal of the review due to the employment of the two authors. A new protocol for a review to cover this topic will be published. This will have a new title and a markedly improved protocol fulfilling new and important developments and standards within the Cochrane Collaboration as well as an improved inclusion and search strategy making it necessary to embark on a completely new review project.
The editorial group responsible for this previously published document have withdrawn it from publication.