Annals of EpidemiologyVolume 9, Issue 6, August 1999, Pages 335-338EditorialAuthor links open overlay panelShow moreShareCitehttps://doi.org/10.1016/S1047-2797(99)00024-1Get rights and contentRecommended articlesReferences (0)Cited by (0)View full textCopyright © 1999 Published by Elsevier Inc.