0. Page 38. Derivation of No Treat-Test Threshold Probability with a costly dichotomous test. If says p[+|D-]B when it should say p[+|D+]B. It should read:
$$\frac{(p[+|D-])C + T}{(p[+|D+])B + (p[+|D-])C} = \text{No Treat-Test Threshold Probability}$$
- Page 322, left column, answer to part 2.5c, 2nd paragraph reads, “Similarly, to get the posttest odds above which we would treat without testing…”
This should read, “Similarly, to get the pretest odds above which we would treat without testing …”
A little lower down, same mistake. It reads, “So the posttest probability = 4.22/5.22…” and should read, “So the pretest probability = 4.22/5.22 …”
Thank you to Songphol Tungjitviboonkun (Epi 204 student in 2024) for spotting this error!
2. Page 339, right column, bottom, answer to part f, there are some percent signs that should not be there and the number 0.9611 is erroneously written as 0.0911. This part of the answer should read:
NB(Treat All) = .0389 – (1/25).9611=0.000456, about 0.05%.
3. Page 340, left column, answer to part g, replace “1/100th“with “1/4th (1.05%/3.98%)” as follows:
This is higher than the treat all strategy, but it’s still only about 1/4th (1.05%/3.89%) as good as being able to admit someone destined to get a stroke without having to admit anyone unnecessarily.