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a 55 yr old man visits his primary care physician with a complaint of urinary infreq. o/e a 1cm nodule is found on his prostate gland. the physician orders a PSA serum test. by common standards, PSA level > 4 ng/ml is considered abn. Using this std, this test has sensitivity of 80% amd specificity of 90%. A recently published epidemio article found that in a cross sectional study , 10% of men of this age have prostate cancer. the result on the patient's PSA is 7ng/ml. what is ur best estimate of the likelihood that this man actually has prostate cancer?

a. 13%
b. 25%
c. 36%
d. 47%
e. 58%
f. 69%
g. 72%
h. 81%

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@drkinjaldesai

could u please explain how u calculated..

oh well its a long way how to do it,,,,,,,,

i have to write and explain actually i cant do it without making a table for sensitivity and specificity

to be short and sweet assume population to be 100 and then start putting values in the 2 by 2 table with 10 as TP + FN and total as 100 and then work ur way through using sensitivity and specificity values given in the question stem,,,,,,u will end up with all the values in 2 x 2 table and what they need is PPV, so get it from the table..............

i hope u got it

@drkinjaldesai

yup..i got it..thx a lot!

thanks to u too,,,,,so that i could revise this one before the D Day