Cystic Fibrosis

Scenario 1: Cystic Fibrosis Use the following scenario to answer questions 1—8. Cystic fibrosis (CF) is a genetic disorder passed down through families. CF causes thick mucus to build up in the lungs and can lead to breathing and digestive problems and life—threatening infections. Early diagnosis at birth can help to reduce the health risks associated with CF and improve projected lifespan and quality of life. Newborn babies are commonly tested for CF by a blood test; however, a less-invasive screening test that does not involve a blood sample has become available. To reduce the pain of blood drawing, you want to evaluate the sensitivity and specificity of the new, noninvasive test, which relies on a sweat sample. Assume that the existing blood test is the gold standard test for CF and that the prevalence of CF among newborns in the US is approximately 1 in 350. With the cooperation of hospitals in Pennsylvania. you administer the sweat screening test to all 145,000 babies born in Pennsylvania this year and obtain the following results. — Goldstandard-BloodTest — —— TOTeL New Screening Test + m 1.229 1635 New screening Test — _ 137,356 131364 144.535 144.999

Of those testing positive on the screening test, how many were truly positive? 

2. Of those testing positive on the screening test, how many were falsely positive?

3. Of those testing negative on the screening test, how many were truly negative?

4. Of those testing negative on the screening test, how many were falsely negative?

5. Calculate the sensitivity of the screening test. Express as a percentage and round to nearest 

whole number (show work).

6. Interpret your sensitivity results in 1 sentence. 

7. Calculate the specificity of the screening test. Express as a percentage and round to nearest 

whole number (show work).

8. Interpret your specificity results in 1 sentence.