Fundamentals of Epidemiology

HLTH 310: Fundamentals of Epidemiology Problem Set 7: Screening, Testing, Evaluation or Screening Programs 1. The following are the results of a diagnostic test. a. Calculate the sensitivity and specificity of the test. b. If the disease is highly contagious and very fatal, would you want to maximize the sensitivity or the specificity? Consider what was discussed in the online lecture and describe one way in which you could improve this measure (either sensitivey or specificity). Disease Status Test Positive Negative Total Positive 240 100 340 Negativ 50 600 660 e Total 300 700 1.000 Many times two or more diagnostic tests are done to diagnosis a disease. The first test is a cheap and relatively easy and non-invasive test, followed by a more expensive an invasive test to verify the results of the first test. In the example below, the first test for breast cancer was a mammogram and that was followed by a surgical biopsy. Only women that had a positive test for breast cancer in the mammogram were called in to have a biopsy and only women that had positive results for both the mammogram and the biopsy were given the diagnosis of breast cancer. Calculate the net sensitivity of the two tests combined when given subsequently? True Results Breast Cancer No Breast Cancer Total 1900 2250 Mammogra Positive 350 m Results Negative |150 7600 7750 Total 500 9500 10,000 True Results Breast Cancer No Breast Cancer Total Biopsy Positive 315 190 505 Results Negaine | 35 1710 1745 Total 350 1900 2250