Question

A new screening test for Type II diabetes was evaluated/validated based on a group of 800 persons, 20% of whom were known to have the disease based on a previous diagnosis. Validation results included the following: (1) the screening test accurately identified 140 persons as having the disease; (2) the screening test accurately ruled out 500 persons as NOT having the disease.

(A)      What is the estimated sensitivity of the new screening test?

(B)      What is the estimated specificity of the new screening test?

(C)      If the test result is positive, what is the chance that a person actually has Type II diabetes?

(D)      If the test result is negative, what is the chance that a person actually does NOT have Type II diabetes?

(E)      Critically evaluate the overall level of validity of this screening test. How, if at all, could it be improved?

(F)      If the actual prevalence in Type II diabetes in this group was 10% (instead of 20%), how would this impact the validity of the screening test?

Please include work to help understand how to approach the question and get to answer

Answer 1

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