Page 1 of 1: Library: Biostatistics: Sensitivity Specificity

Nicki · Credits: 2463 My Scrapbook My Reading List 7 Books

Disease Present Disease Absent

Test a b
Positive

Test c d
Negative

Sensitivity –> TRUE POSITIVE =a/(a+c)

Specificity –> TRUE NEGATIVE=c/(b+d)

positive predictive value
(the probability that a person has the disease given a positive test) = a/(a+b)

negative predictive value
(the probability that a person does not have the disease given a negative test) =d/(d+c)

AHMADDD · Credits: 5921 My Scrapbook My Reading List 1 Books

Number needed to Treat (NNT)

If the risk of dying from a MI after "standard treatment" is 10%, and a new treatment reduces this to 8%.

Absolute Risk Reduction:: 10 - 8 % = 2%

Relative Risk Reduction:: {(10-8 / 10)x100}= 20%

NNT: {(1/Absolute risk reduction) x100} = 50

faridi · Credits: 1819 My Scrapbook

great job i was very confused after seeing stat mcqs now i guess i can face them with ur valuable notes

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