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Ann Thorac Surg 2001;72:1795-1796
© 2001 The Society of Thoracic Surgeons

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Correspondence

Simulation techniques to support prosthetic valve choice in aortic valve replacement: Reply

^a Department of Surgery (HB7800), Dartmouth Medical School, One Medical Center Dr, Lebanon, NH 03756, USA

e-mail: nancy.j.hirkmeyer{at}dartmouth.edu

To the Editor

Given the complex nature of their underlying models and assumptions, independent validation greatly enhances the value of clinical decision analyses. In this regard, we appreciate the efforts of Takkenberg and colleagues in validating our findings.

Takkenberg and associates also use sensitivity analysis to underscore the importance of assumptions about excess mortality (relative to the general population) in patients undergoing valve replacement. Whether to use additive (as we did in our analysis) or multiplicative models is a matter of some debate [1]. Takkenberg and coworkers have shown that applying a multiplicative model substantially reduces life expectancy estimates in patients under 70. The net effect is to increase the apparent benefit of tissue valves and reduce the age at which tissue valves are preferred over mechanical valves. In our analysis, the decision was similarly sensitive to varying estimates for a number of input variables for patients between the ages of 60 and 70.

Even with different assumptions, however, both of our analyses reach a similar conclusion: A large proportion of the patients who are currently receiving mechanical valves would do better with tissue valves.

References

1. Kuntz K., Weinstein M. Life expectancy biases in clinical decision modeling. Med Decis Making 1995;15:158-169.[Abstract/Free Full Text]

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Birkmeyer, N. J.O. Search for Related Content PubMed Articles by Birkmeyer, N. J.O. Related Collections Related Article