Consider the following 'true' and misclassified collected data from a hypothetical case-control study of statin use and Alzheimer's disease. Assume the sensitivity of exposure measurement is 100%.

No misclassification ("Truth")

Alzhemers disease and Statin use =40

No Alzheimers disease and statin use =30

Alzheimers disease and no statin use = 50

No Alzhmeir disease and no statin use = 70

Misclassification

Alzhemers disease and Statin use =45

No Alzheimers disease and statin use =50

Alzheimers disease and no statin use = 45

No Alzhmeir disease and no statin use = 50

a. Calculate the specificity of exposure among cases with Alzheimers

b. Calculate the specificity of exposure among controls without Alzheimers

c. Which of the following correctly describes the type of misclassification:

a.Nondifferential misclassification of disease.

b.Differential misclassification of disease

c.Nondifferential misclassification of exposure

d.Differential misclassification of exposure