NR503: Population Health, Epidemiology, & Statistical Principles Week 2: Epidemiology and Biostatistics to Inform Advanced Practice Nursing

NR503: Population Health, Epidemiology, & Statistical Principles Week 2: Epidemiology and Biostatistics to Inform Advanced Practice Nursing TD3: Please provide a summary of the case or information you have discussed this week The ability to classify individuals into the correct disease status depends on the quality, and accuracy of the screening or the diagnostic test. Ideally, a good screening test will be able to tell us which subjects have the disease and vice versa, which will lead to earlier treatment and that this, in turn, will lead to a better outcome. The ideal screening test must also be valid and reliable. The validity of a test is defined as its ability to distinguish between who has a disease and who does not (Gordis, 2014 p, 88). An ideal screening test is exquisitely sensitive (high probability of identifying correctly those who have the disease) and extremely specific (high probability that those without the disease will screen negative). If a test is reliable, it gives consistent results with repeated tests. When evaluating the feasibility or the success of a screening program, one should also consider the positive and negative predictive values. Positive predictive value is the proportion of persons with a positive test that are true positive actually have the disease (true positive) whereas negative predictive value is the proportion of those who test negative who do not have (Gordis, 2014 p, 100). Predictive value of a test is an important issue. Physician used it to enhance his/her ability to make a correct diagnosis. One needs to consider what happens to the people who had a positive screening test but turned out not to have the disease (false positives) and to the people who had a negative screening test but turned out to have the disease (false negatives). Reference Gordis, L. (2014). Epidemiology (5th ed.). Philadelphia, PA: Elsevier