When are observational studies as credible as randomised trials?

Affiliations

Jan P Vandenbroucke. Lancet. 2004.

. 2004 May 22;363(9422):1728-31.

doi: 10.1016/S0140-6736(04)16261-2.

¹ Department of Clinical Epidemioloy, Leiden University Medical Centre, Bldg 1 C9-P, 2300 RC Leiden, Netherlands. J.P.Vandenbroucke@lumc.nl

No abstract available

Comment in

Beyond randomised versus observational studies.
Concato J, Horwitz RI. Concato J, et al. Lancet. 2004 May 22;363(9422):1660-1. doi: 10.1016/S0140-6736(04)16285-5. Lancet. 2004. PMID: 15158623 No abstract available.
Observational versus randomised trial evidence.
Wiseman M. Wiseman M. Lancet. 2004 Aug 28-Sep 3;364(9436):755-6; author reply 756-7. doi: 10.1016/S0140-6736(04)16927-4. Lancet. 2004. PMID: 15337395 No abstract available.