✦ LIBER ✦

Selection bias and treatment heterogeneity in clinical trials

✍ Scribed by Nicholas T. Longford

Publisher: John Wiley and Sons
Year: 1999
Tongue: English
Weight: 151 KB
Volume: 18
Category: Article
ISSN: 0277-6715
DOI: 10.1002/(sici)1097-0258(19990630)18:12<1467::aid-sim149>3.0.co;2-h

No coin nor oath required. For personal study only.

✦ Synopsis

A common perception about many commercially available medical treatments is that they are e!ective for every patient having the relevant indication and that developers have provided the regulatory authorities with evidence of such a property. We show that the standard of evidence is much lower and that the standard is appropriate only when the treatment e!ects are almost constant. We discuss the implications on the design and analysis of clinical trials if the standards were made to correspond with the common perception. We conclude that the evidence of positive mean treatment e!ect should be accompanied by evidence of limited dispersion of the e!ects and by a sensitivity analysis that explores the impact of the selection bias in recruitment.

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