Author + information
- Alan D. Guerci, MD, FACC⁎ ( and )
- David Newstein, DrPH
- ↵⁎St. Francis Hospital, 100 Port Washington Boulevard, Roslyn, New York 11576
In reply to Dr. Boyar’s letter, using data from Figure 2 in our study (1) and rounding off, we calculated a sensitivity of 0.94 and a specificity of 0.33 for all calcium scores ≥1. The values in our Figure 2, 0.91 and 0.39, respectively, differ slightly because the computer program that generated Figure 2 grouped all square roots less than the next whole number with the previous whole number. Thus, calcium scores of 1, 2, and 3, with square roots of 1.0, 1.4, and 1.7, respectively, were all plotted as corresponding to a value of 1.0 on the abscissa. Calcium scores of 4 to 8, with square roots of 2.0 to 2.8, were lumped together as 2, and so on. We apologize for any confusion created by Figure 2 in our report (1).
We are not aware of any standard that a threshold means > the threshold value rather than ≥ the threshold value. In the case of calcium scores of 0, we chose ≥0 because this makes a useful reductio ad absurdumpoint about the test, and because we believed the rest of the graph makes better sense if the threshold values were included.
- American College of Cardiology Foundation