TY  - JOUR
T1  - Clear heads and bayesian tales: Predictive value and the coin toss?-reply
AU  - BROWN GW
Y1  - 1989/09/01
N1  - 10.1001/archpedi.1989.02150210017010
JO  - American Journal of Diseases of Children
SP  - 1001
EP  - 1001
VL  - 143
IS  - 9
N2  - —Dr Mauro has pointed out a very interesting aspect of the algebra of calculating positive predictive values or PV +.PV+ is the probability that this subject has the disease tested for (D +) given that the test for the disease is positive (T +). PV+ can be written as prob(D + T +) = the probability of the disease given a positive test.This is a classic Bayes' formula issue and a subtle one that I have not seen discussed anywhere in my reading. For the record, I will go through the algebra in case someone challenges Dr Mauro's assertions.If you flip a coin instead of performing a test, you will get pr(T + D +) of.50; that is, the probability of a positive test T+ is the probability of, say, "heads."Also, the probability of a positive test among subjects without the disease, pr(T + D-), will also be
SN  - 0002-922X
M3  - doi: 10.1001/archpedi.1989.02150210017010
UR  - http://dx.doi.org/10.1001/archpedi.1989.02150210017010
ER  -