This post is ancient, but I have a question. The reason for using the issue number when the volume isn't continuously paginated, is that the page numbers may exist for any issue, so page number for such a volume isn't specific. However, Cochrane isn't continuously paginated by issue, either. All articles start on page 1, so page numbers for a given issue are just as unspecific. Shouldn't you just drop volume, issue and page numbers altogether? I mean, neither are very helpful for locating the article, and you still have the DOI.