We found a matchYour institution may have access to this item. Find your institution then sign in to continue.TitleWhen are observational studies as credible as randomised trials?AuthorsVandenbroucke, Jan PPublicationLancet (London, England), 2004, Vol 363, Issue 9422, p1728ISSN1474-547XPublication typeJournal ArticleDOI10.1016/S0140-6736(04)16261-2