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Editorial
. 2001 Apr 14;322(7291):879-80.
doi: 10.1136/bmj.322.7291.879.

Any casualties in the clash of randomised and observational evidence?

J P Ioannidis, A B Haidich, J Lau
Editorial

Any casualties in the clash of randomised and observational evidence?

J P Ioannidis et al. BMJ. .
No abstract available

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Figures

Figure
Figure
Comparison of pooled odds ratio from observational studies against pooled odds ratio from randomised controlled trials on the same question. The 25 questions with binary outcomes are derived from Benson and Hartz and Concato et al; one question had three comparisons, and another topic is not included since the outcome was not dichotomous
See this image and copyright information in PMC

References

    1. Benson K, Hartz AJ. A comparison of observational studies and randomized, controlled trials. N Engl J Med. 2000;342:1878–1886. - PubMed
    1. Concato J, Shah N, Horwitz RI. Randomized, controlled trials, observational studies, and the hierarchy of research designs. N Engl J Med. 2000;342:1887–1892. - PMC - PubMed
    1. Ioannidis JPA, Cappelleri JC, Lau J. Issues in the comparisons of meta-analysis and large trials. JAMA. 1998;281:1089–1093. - PubMed
    1. Pocock SJ, Elbourne DR. Randomized trials or observational tribulations? N Engl J Med. 2000;342:1907–1909. - PubMed
    1. Lau J, Ioannidis JPA, Schmid CH. Summing up evidence: one answer is not always enough. Lancet. 1998;351:123–127. - PubMed

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