TY - CHAP M1 - Book, Section TI - Chapter 6. Diagnostic Testing A1 - Greenberg, Raymond S. A1 - Daniels, Stephen R. A1 - Flanders, W. Dana A1 - Eley, John William A1 - Boring, John R. Y1 - 2005 N1 - T2 - Medical Epidemiology, 4e AB - The sensitivity of a diagnostic test is the likelihood that persons with the disease of interest will have positive test results. The specificity of a diagnostic test is the likelihood that persons who do not have the disease of interest will have negative test results. Positive predictive value measures the likelihood of having the disease of interest among those whose diagnostic test results are positive. Negative predictive value is the likelihood of not having the disease of interest among those whose diagnostic test results are negative. Likelihood ratios can be used to measure the extent to which the likelihood of the disease of interest is changed by the results of a diagnostic test. The area under a receiver operating characteristic (ROC) curve can be used to assess the performance of a diagnostic test. Screening for a particular disease is conducted in order to detect the disease at an earlier stage than would occur through routine methods. An error in the evaluation of a screening test, known as lead time bias, can occur when persons with disease detected by screening appear to live longer simply because of the earlier recognition of their illnesses. An error in the evaluation of a screening test, known as length-biased sampling, can occur when persons with disease detected by screening appear to live longer simply because they have more slowly progressing illnesses. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accesspharmacy.mhmedical.com/content.aspx?aid=545607 ER -