High Yield Warm-up Questions: Epidemiology GENERAL PRINCIPLES SET 8: EPIDEMIOLOGY What are the similarities and differences between incidence rate and attack rate? A study is conducted at a university hospital where 5,000 high-risk men without prostate cancer are followed forward in time The study is started on January 1, 2007 and ends on December 31, 2011 Over this period of time, 200 men develop prostate cancer What is the correct way to present these findings? If a new strain of HIV suddenly develops that is resistant to all current medications, what will be the effect on both incidence and prevalence over a specific period of time? A patient with metastatic melanoma is enrolled in a clinical trial Before signing up for the trial, the patient was informed that in this particular phase of the trial researchers will be testing efficacy and occurrence of side effects in a large group of patient volunteers What is the current phase of this trial? A researcher is trying to determine if going to a tanning salon increases the risk of skin-related cancer She enrolls 100 women who regularly plan on going to a tanning salon at least twice a week throughout the upcoming year and 100 women who not plan to use artificial tanning or natural tanning methods What type of study is this? 1 High Yield Warm-up Questions: Epidemiology Researchers tested a new at home herpes simplex test The test was initially used in 300 patients with confirmed genital herpes and 300 patients without genital herpes The test correctly identified 210 patients with herpes and 280 patients without genital herpes What is the sensitivity of the test? Researchers tested a new at home herpes simplex test The test was initially used in 300 patients with confirmed genital herpes and 300 patients without genital herpes The test correctly identified 210 patients with herpes and 280 patients without genital herpes What is the specificity of the test? Researchers tested a new at home herpes simplex test The test was initially used in 300 patients with confirmed genital herpes and 300 patients without genital herpes The test correctly identified 210 patients with herpes and 280 patients without genital herpes What is the positive predictive value of the test? With respect to the treatment of a given disease state: Would a researcher obtain more information about the treatment of this condition by performing a single randomized clinical trial or performing a meta-analysis? 10 A researcher performs two randomized controlled clinical trials in the same patient population The results of the two trials are as follows: Trial 1: Drug X is found to be superior to Drug Y Trial 2: Drug Y is found to be superior drug Z Based on this information alone, what can be said about the relationship between Drug X and Drug Z? High Yield Warm-up Questions: Epidemiology 11 A researcher performs two randomized controlled clinical trials in the same patient population The results of the two trials are as follows: Trial 1: Drug X is found to be superior to Drug Y Trial 2: Drug Y is found to be inferior to drug Z Based on this information alone, what can be said about the relationship between Drug X and Drug Z? 12 A company develops a new diagnostic test This company then performs a research study When the results of the study are analyzed, would the company prefer that their new diagnostic test be classified as being precise or accurate? 13 Researchers tested a new hepatitis C test The test was initially used in 500 patients with confirmed hepatis C and 400 patients without hepatitis C The test correctly identified 490 patients with hepatis C and 380 patients without hepatitis C What is the accuracy of the test? 14 Researchers tested a new hepatitis C test The test was initially used in 500 patients with confirmed hepatis C and 400 patients without hepatitis C The test correctly identified 490 patients with hepatis C and 380 patients without hepatitis C Once the accuracy of the hepatitis C test was calculated, what can be said about its precision? 15 A researcher is trying to determine the incidence of hypercholesterolemia in the general population He offers a free cholesterol screening outside a local fast food restaurant What type of bias is most likely to occur in his study? 3 High Yield Warm-up Questions: Epidemiology 16 A researcher is trying to determine if wearing more comfortable clothes to work will increase productivity The researcher first evaluates the productivity of each worker based on previous production logs and then evaluates each worker throughout the day At the end of the month, she compares the productivity logs from each worker and determines that the productivity has increased on average 22% over the past month What type of bias has likely occurred? 17 A manufacturer has just developed an at home genetic screening test for Alzheimer’s disease After performing a controlled clinical trial, this test was shown to detect Alzheimer’s disease two years earlier than all current diagnostic methods When the results of the trial are published, the researchers claim that Alzheimer’s patients using this test are able to live longer when they are diagnosed with their new test This last statement is an example of what kind of bias? These question sets are intended to be completed before viewing the High Yield course lectures Video explanations can be found on the Warm-up Questions page within the online High Yield course For further review of the topics covered in this set, refer to the following lecture: Epidemiology and Biostatistics: • Epidemiology ... Yield course For further review of the topics covered in this set, refer to the following lecture: Epidemiology and Biostatistics: • Epidemiology ... can be said about the relationship between Drug X and Drug Z? High Yield Warm-up Questions: Epidemiology 11 A researcher performs two randomized controlled clinical trials in the same patient... precision? 15 A researcher is trying to determine the incidence of hypercholesterolemia in the general population He offers a free cholesterol screening outside a local fast food restaurant What