Concept explainers
Suppose a new test is proposed to identify patients with a specific condition.
One specimen is obtained from each of 220 subjects in the population to whom the test will be applied. Fifty-one (51) subjects have the condition and 169 do not, according to a gold standard used to assess the presence of the condition (referred to as a reference standard below). The following results are obtained:
Suppose a quality score is constructed for the test. A true positive identified by the test is given a score of +20. A
true negative identified by the test is given a score of +10. A false positive identified by the test is given a score of -5. A false negative identified by the test is given a score of-20.
The FDA will approve the new test if the lower bound of a 90% Cl for the
Hint: Assume that the score distribution is approximately normal or that the central limit theorem is applicable.
Hint: Assume that a t distribution with > 200 df is approximately normal.
Hint: To compute the mean and variance from grouped data, use the formulas
where xi is the ith score value, fi is the frequency of the ith score value, k = number of score values, and
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Fundamentals of Biostatistics
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw HillCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning