BMJ  2005;330:791-792 (2 April), doi:10.1136/bmj.330.7494.791-b

Letter

Need for expertise based randomised controlled trials

Expertise based design has shortfalls

EDITOR—Devereaux et al discussed the need for expertise based randomised controlled trials for surgical procedures.¹

Firstly, the use of expertise based designs does not necessarily enhance the validity of a surgical trial. Surgical outcome does not depend solely on the operation; other factors that influence the results of an operation are heterogeneous and immeasurable (postoperative management, the surgical team, equipment). A different bias is introduced by the expertise based design, the influence of the overall performance of surgeon A v B, and in this regard, expertise based design is not necessarily a more valid comparison of operation A v B.

Secondly, the use of expertise based designs does not necessarily enhance the applicability of a surgical trial. The expertise based design assumes that an operation will only be performed by a select few. This is rarely the case, and hence the results will not reflect the true performance of an operation introduced to the general public (performed by a variety of surgeons).

Moreover, the results of expertise based design trials do not take into account any learning curve that exists when a new operation is introduced. The initial rates of adverse outcomes are higher when a surgeon refines an existing operative technique,² never mind a new one.

A solution is to perform a randomised trial that has a balanced surgical expertise in both arms in proportions reflective of the population that will perform the operations. Academics can analyse the "expertise" subgroup, while the rest of us can look at the overall results to determine how an operation will really perform.

Papworth Hospital, Papworth Everard, Cambridge CB3 8RE eric.lim{at}cvsnet.org

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Competing interests: None declared.

References

1. Devereaux PJ, Bhandari M, Clarke M, Montori VM, Cook DJ, Yusuf S, et al. Need for expertise based randomised controlled trials. BMJ 2005;330: 88. (8 January.)[Free Full Text]
2. Bridgewater B, Grayson AD, Au J, Hassan R, Dihmis WC, Munsch C, Waterworth P. Improving mortality of coronary surgery over first four years of independent practice: retrospective examination of prospectively collected data from 15 surgeons. BMJ 2004;329: 421.[Abstract/Free Full Text]

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