# In Irvine, 11,477 people have G6PD deficiency out of a total population of 149,058.

## In Irvine, 11,477 people have G6PD deficiency out of a total population of 149,058.

In Irvine, 11,477 people have G6PD deficiency out of a total population of 149,058. 150 150 Peter

Pre-Work: Home Screening Tests

Instructions: Read the article “Understanding Sensitivity and Specificity with the Right Side of the Brain” along with the scenario below and then answer the following questions.

Scenario: In Irvine, 11,477 people have G6PD deficiency out of a total population of 149,058. As a pharmacy owner in the city, two separate companies have approached you to purchase/place their screening test in your pharmacy. Tests A requires 35 µL of blood, results are available in 5 minutes using the device, and costs \$40. Test B requires saliva from a mouth swab, the sample needs to be mailed back to the company for analysis (3 business days for results), and costs \$15. The technical specifications of each test is listed below:

Test A can correctly identify 5000 of the 11,477 with G6PD deficiency, but also identifies 13,500 healthy people as having G6PD deficiency

Test B can correctly identify 9000 of the 11,477 with G6PD deficiency, but also identifies 27,000 healthy people as having G6PD deficiency

Questions:

1. For each test, calculate its sensitivity, specificity, PPV, and NPV

2. If a patient were to purchase this test, clearly and concisely describe in patient friendly language what sensitivity and specificity mean/measure

3. If a patient were to purchase this test, clearly and concisely describe in patient friendly language what positive and negative predictive value mean/measure

4. If the prevalence of G6PD deficiency were to increase, how would this affect the sensitivity/specificity of these tests?

5. If the prevalence of G6PD deficiency were to decrease, how would this affect the positive/negative predictive values of these tests?