5. Gen-Probe's Aptima Combo 2 Assay is used to simultaneously detect chlamydia and gonorrhea in individuals....

Transcribed Image Text:

5. Gen-Probe's Aptima Combo 2 Assay is used to simultaneously detect chlamydia and gonorrhea in individuals. In their product insert, they provide information on the accuracy of the diagnostic test. Let's consider 676 of symptomatic males that provided swab specimens for chlamydia testing. Of these 676 individuals, 190 tested positive and were judged truly positive. Note that the results from a combination of other testing procedures were used to make the true diagnosis. Similarly, 464 individuals were truly negative and tested negative. There were 22 errors with 15 positive tests for truly negative individuals and 7 negative tests for truly positive individuals. The purpose of this problem is to calculate confidence intervals for sensitivity (Se) and specificity (Sp) measures. The sensitivity is defined as the proportion of truly positive individuals that test positive, and the specificity is defined as the proportion of truly negative individuals that test negative. Ideally, it is desirable to have Se and Sp close to 1 as possible. Point estimates for the sensitivity and the specificity are respectively Se = 0.964467 and Sp = 0.9686848. (a) The product insert give Clopper-Pearson intervals. Suggest possible reasons why it gives only the Clopper-Pearson interval rather than the Wald, Wilson, or Agresti-Coull intervals. (b) Compute the 95% Clopper-Pearson intervals for Se and for Sp. Interpret the intervals. 5. Gen-Probe's Aptima Combo 2 Assay is used to simultaneously detect chlamydia and gonorrhea in individuals. In their product insert, they provide information on the accuracy of the diagnostic test. Let's consider 676 of symptomatic males that provided swab specimens for chlamydia testing. Of these 676 individuals, 190 tested positive and were judged truly positive. Note that the results from a combination of other testing procedures were used to make the true diagnosis. Similarly, 464 individuals were truly negative and tested negative. There were 22 errors with 15 positive tests for truly negative individuals and 7 negative tests for truly positive individuals. The purpose of this problem is to calculate confidence intervals for sensitivity (Se) and specificity (Sp) measures. The sensitivity is defined as the proportion of truly positive individuals that test positive, and the specificity is defined as the proportion of truly negative individuals that test negative. Ideally, it is desirable to have Se and Sp close to 1 as possible. Point estimates for the sensitivity and the specificity are respectively Se = 0.964467 and Sp = 0.9686848. (a) The product insert give Clopper-Pearson intervals. Suggest possible reasons why it gives only the Clopper-Pearson interval rather than the Wald, Wilson, or Agresti-Coull intervals. (b) Compute the 95% Clopper-Pearson intervals for Se and for Sp. Interpret the intervals.

Answer rating: 100% (QA)

Answer a There are several reasons why the product insert might give only the ClopperPearson interva... View the full answer