Journal of Clinical EpidemiologyVolume 52, Issue 9, September 1999, Pages 813-825DiscussionAuthor links open overlay panelShow moreShareCitehttps://doi.org/10.1016/S0895-4356(99)00040-2Get rights and contentFirst page previewClick to open first page previewView PDFRecommended articlesReferences (0)Cited by (0)View full textCopyright © 1999 Published by Elsevier Inc.