HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Erratum (v132,p11) Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Author home page(s): Endre Bodnar Eugene H. Blackstone Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bodnar, E. Articles by Blackstone, E. H. Search for Related Content PubMed Articles by Bodnar, E. Articles by Blackstone, E. H. Related Collections Education History

J Thorac Cardiovasc Surg 2006;131:1-3
© 2006 The American Association for Thoracic Surgery

Editorial

An "actual" problem: Another issue of apples and oranges

^a Editor in Chief, The Journal of Heart Valve Disease; Director of Clinical Research, Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation, Cleveland, Ohio.
^b Department of Quantitative Health Sciences, The Cleveland Clinic Foundation, Cleveland, Ohio.

Received for publication November 1, 2005; accepted for publication November 22, 2005.

^_* Address for reprints: Endre Bodnar, MD, Crispin House, 12/A South Approach, Moor Park, Northwood, HA6 2ET, United Kingdom. (Email: bodnarendre@aol.com).

The first 20% of the full text of this article appears below.

"The road to hell is paved with good intentions"

(Proverb)

When deliberating on replacement heart valves, two important questions spring to mind. One is, "How does the replacement valve perform in terms of time-related probability of occurrence of failure and other complications attributable to the device itself?" Answering this question is the basis for making valid comparisons among different types and models of prosthesis. The second is, "How likely is it that a patient with a replacement device will survive to experience a given device-related complication?" Because the make-up (patient mix or profile) of various groups of patients receiving heart valves differs with respect to risk factors for mortality, the number of patients living to experience a given complication will differ and will not be comparable, even though the attributes of the device remain the same.

Clearly these two questions differ, as do their answers; one addresses intrinsic properties of the device; the other places these properties into the context of specific patients or groups of patients. One is apple, the other is orange, and they are not to be confused.

Actuarial analysis, ¹ whether by the life table method, ² Kaplan-Meier product limit calculation, ³ or a number of other variants, was originally introduced to assess survival probability in a population where not everybody is dead at the time of inquiry. ⁴ The method offered itself as eminently suitable when the time-related assessment of non-fatal events became a necessity. ⁵ In this case, however, there is a caveat. Due to its underlying statistical and mathematical basis, actuarial assessment of a non-fatal event assumes that the entire patient population will live forever. . . . [Full Text of this Article]

This article has been cited by other articles:

				G. L. Grunkemeier, J. J.M. Takkenberg, W.R. E. Jamieson, and D. C. Miller Reporting "actual freedom" should not be banned. J. Thorac. Cardiovasc. Surg., February 1, 2008; 135(2): 460 - 462. [Full Text] [PDF]

				G. L. Grunkemeier, R. Jin, M. J.C. Eijkemans, and J. J.M. Takkenberg Actual and Actuarial Probabilities of Competing Risks: Apples and Lemons Ann. Thorac. Surg., May 1, 2007; 83(5): 1586 - 1592. [Abstract] [Full Text] [PDF]