Re: It boggles the mind why.........

Assume that 1000 individuals are administered the test. Of these people, only 1 person will probably have the disease. Of the other 999 people without the disease, 50 (mathematically the number is 49.95) will still test positive because of the test’s false positive of 5%. Therefore, 51 (mathematically the number is 50.95) people will test positive in a group of 1000 people. But only 1 person in those 51 people actually has the disease.

Therefore, the chance that a person found to have a positive test result actually has the disease P(D/POS) = 1/51 = 0.0196 , about 2% of all positives.

In the case of breast cancer, it occurs less than 1 in 1000, more like 1 in 1500. In the case of mammograms, the false positive rate is much higher than 5%. The numbers are out there, and one can readily do the math.

Why women subject themselves to a procedure with such a poor accuracy, has few explanations. Probably, very few know the truth about the numbers, and are instilled with fear from various sources. That is how business works, to maximize profit, in La-La land.

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