Figures
Tables 1, 4, and 5 are incorrectly shaded, and the shading does not denote negative statistical significance. The correct versions of Tables 1, 4, and 5 can be viewed below, with lines typeset in boldface indicating negative statistical significance.
The images for Figures 6 and 7 are incorrectly switched. The image that appears as Figure 6 should be Figure 7, and the image that appears as Figure 7 should be Figure 6. The figure legends appear in the correct order. The correct Figure 6 and Figure 7 can be viewed below.
Cartoon illustrating two distinct, unrelated, values that are both called “threshold”. The statistically optimal threshold value of a continuous risk factor for subdividing the population (left panel) has no relevance to the question of what value of a risk factor should be used to decide whether to intervene or not (right panel). The former, the “observed prognostic threshold”, will generally be the middle of whatever population happens to be studied, if mortality varies roughly linearly with the risk factor. The latter, the “ideal clinical decision-making threshold”, will critically depend also on the outcomes with intervention, and will move as the success of the package of medical therapy (and of transplantation) changes with time. There is no sense in using one as a proxy for the other.
The shaded areas represent the 95% confidence intervals for this function. Flexible non-linear functions have numerous benefits over categorization, including improved precision, avoidance of assumption of a discontinuous relationship, maximisation of applicability to the individual and importantly avoidance of giving other variables or interactions artificially high weights. Inspection of the resulting plots above can make obvious the lack of a discontinuity in risk.
In the Discussion section, the third paragraph under the title “Two easily-confused but different types of ‘threshold,’” the first sentence states “That these two types of threshold differ is sketched in Figure 5, which imagines a situation where, with only medical therapy, mortality falls smoothly with rising peak VO2, while with transplantation mortality is at a fixed level.” This should refer to Figure 6, which can be seen below.
Also in the Discussion section, under “Prognostic studies,” the second sentence of the first paragraph states “For example, a flexible nonlinear function can be fitted and displayed with confidence bands for incremental log odds over the whole span of the marker; seeking a point such that risk is flat on both sides of that point but the risk on one side is much different from the risk on the other side (Figure 6).” This should refer to Figure 7, which can be seen below.
Reference
- 1. Giannoni A, Baruah R, Leong T, Rehman MB, Pastormerlo LE, et al. (2014) Do Optimal Prognostic Thresholds in Continuous Physiological Variables Really Exist? Analysis of Origin of Apparent Thresholds, with Systematic Review for Peak Oxygen Consumption, Ejection Fraction and BNP. PLoS ONE 9(1): e81699
Citation: The PLOS ONE Staff (2014) Correction: Do Optimal Prognostic Thresholds in Continuous Physiological Variables Really Exist? Analysis of Origin of Apparent Thresholds, with Systematic Review for Peak Oxygen Consumption, Ejection Fraction and BNP. PLoS ONE 9(9): e105175. https://doi.org/10.1371/journal.pone.0105175
Published: September 17, 2014
Copyright: © 2014 The PLOS ONE Staff. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.