Clinical Trials in Urology
Central to evidence-based practice is the concept of a hierarchy of evidence, with the randomized, controlled trial providing the highest level of evidence among individual studies. Several key features of randomized controlled trials provide methodological safeguards against the introduction of bias. Among trial design elements, the most important are randomization, allocation concealment, and blinding. In addition, equal treatment of groups (apart from the experimental intervention) and complete follow-up are critical aspects of trial design. A number of analytic elements also protect against bias. Appropriate sample size calculations minimize underpowered studies. Intention to treat analysis protects against non-random loss to follow-up. Authors should report the size and precision of the observed treatment effect. Finally, it is important to interpret subgroup analyses cautiously, as multiple analyses increases the risk of false positive findings. Assessment of these trial features when interpreting the urologic literature will lead to a more evidence-based practice. © 2010 Blackwell Publishing Ltd.
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International Standard Book Number 13 (ISBN-13)
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