[Revista Española de Cardiología suplementos. A new venture for the editorial committee].

Supplements are scholarly monographs on specific subjects that scientific journals usually publish quite regularly. They always appear as separate issues of the “mother journal” and each issue is independently financed. They are an ideal medium to disseminate the contents of symposia, provide a vehicle for continuing education or updates on specific topics, for the Societies’ Working Group or Scientific Section consensus documents, and for clinical practice guidelines, too. As supplements always have special financial support, the International Committee of Medical Journal Editors1 recommends the following guidelines: the editor should ensure the independence of the scientific content and that good editorial practices are maintained in relation with the source of finance; the editor should approve the subject index and collaborate with the guest editor of each supplement; it is reasonable to set up external peer review for each supplement; final supplement content cannot be changed at the request of the sponsor; the type of financial support should be clearly stated in each supplement and advertising should follow the same norms that apply to scientific journals; supplement pages should be numbered independently to distinguish them from the journal.