We welcome original articles from any part of the world. The papers are assessed by members of the Editorial Board and our international panel of expert reviewers, then either accepted for publication or rejected by the Editor. We receive over 2000 submissions each year and accept about 250 for publication, many after revisions recommended by the reviewers, editors or statistical advisers. A decision usually takes between six and eight weeks. Each paper is assessed by two reviewers with a special interest in the subject covered by the paper, and also by members of the editorial team. Controversial papers will be discussed at a full meeting of the Editorial Board. Publication is between four and six months after acceptance.