Exam

NR 503 Week 4 Midterm Review Guide (Chapter 5-6)

Question: In a community-based hypertension testing program called HT-Aware, the detection level for high blood pressure is set at 140mmHg for systolic... [Show More] blood pressure. A separate testing program called HT-Warning in the same community sets the level at 130mmHg for high systolic blood pressure. Which statements are likely to … true? Question: A school nurse examined a population of 1,000 children in an attempt to detect nearsightedness. The prevalence of myopia in this population is known to … 15%. The sensitivity of the examination is 60% and its specificity is 80%. All children labeled as “positive” (i.e., suspected of having myopia) by the school nurse are sent for examination by an optometrist. The sensitivity of the optometrist’s examination is 98% and its specificity is 90%. How many children are labeled “positive” by the school nurse? Question: Same info- What is the positive predictive value (PPV) of the school nurses’s exam? Question: How many children will … labeled myopic following the optometrist’s exam? Question: What is the positive predictive value (PPV) of the optometrist’s exam? Question: What is the negative predictive value (NPV) of the optometrist’s exam? Question: What is the overall sensitivity of the sequential examinations? Question: What is the overall specificity of the sequential examinations? Question: What would … the positive predictive value (PPV) of the exam for myopia if the optometrist tested all 1,000 children? Question: Which of the following improves the reliability of diabetes screening tests? Question: A prostate specific antigen (PSA) test is a quick screening test for prostate cancer. A researcher wants to evaluate it using two groups. Group A consists of 1,500 men who had biopsy-proven adenocarcinoma of the prostate while group B consists of 3,000 age- and race-matched men all of whom showed no cancer at biopsy. The results of the PSA screening test in each group is shown in the table. What is the sensitivity of the PSA screening test in the combined groups? Question: Same info- what is the specificity of the screening test in the combined groups? Question: What is the positive predictive value (PPV) of the screening test in the combined groups? Question: The PSA screening test is used in the same way in two equal-sized populations of men living in different areas of the United States, but the proportion of false positives among those who have a positive PSA test in the first population is lower than that among those who have a positive PSA test in the second population. What is the likely explanation for this finding? Question: Test A has a sensitivity of 95% and a specificity of 90%. Test B has a sensitivity of 80% and a specificity of 98%. In a community of 10,000 people with 5% prevalence of the disease, Test A has always been given before Test B. What is the best reason for changing the order of the tests? Question: Two neurologists, Drs. J and K, independently examined 70 magnetic resonance images (MRIs) for evidence of brain tumors. As shown in the table below, the neurologists read each MRI as either “positive” or “negative” for brain tumors. Question: What is the estimate of kappa for the reliability of the two doctors’ test results? Question: This table represents the results of coronary magnetic resonance (CMR) angiography compared to x-ray angiography (the gold standard in diagnosis of coronary artery disease) in a high-risk population of patients scheduled to undergo x-ray angiography for suspected coronary artery disease. Question: After reviewing the results of the test comparison, an epidemiologist decides that the specificity of the test is too low. Using the same CMR images, he raises the cutoff value for a positive test to increase the specificity. What is the likely effect on the sensitivity? Question: In comparing the mammography readings of two technicians who evaluated the same set of 600 mammograms for presence of breast cancer from a generally representative sample of women from the population, Question: In a country with a population of 16 million people, 175,000 deaths occurred during the year ending December 31, 2005. These included 45,000 deaths from tuberculosis (TB) in 135,000 persons who were sick with TB. Assume that the population remained constant throughout the year. What was the annual mortality rate for the country during 2005? Question: Assume that the population remained constant throughout the year. What was the case-fatality rate (CFR) from TB during 2005? Question: What is the proportionate mortality ratio (PMR) for TB during 2005? The PMR is the number of deaths due to a specific cause divided by all deaths. In this example, the PMR equals 45,000 TB deaths divided by 175,000 deaths, or approximately Question: Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? Question: Which of the following statements pertains to relative survival? Question: What was the probability of surviving the second year given survival to the end of the first year? Question: What was the cumulative probability of surviving after only 2 years of follow-up? Question: An important assumption in this type of analysis is that: Question: Tables not included Question: Tables not included Question: Which of the following is a key assumption involved in the use of life-table analysis? Question: Which of the following is a measure of disease prognosis? Question: In 2003, Sudden Acute Respiratory Syndrome (SARS) appeared in several countries, mainly in Asia. The disease was determined to have been caused by a virus that could … spread from person –to person from the index case occurring in mainland China. This table reflects the total number of reported cases of SARS and deaths among those cases as best as can … determined. What is the overall case-fatality rate for the worldwide epidemic of SARS? Question: Based on the table, we can conclude that the case-fatality rate (CFR) in Vietnam: Question: Following a revision in the case definition, more persons were found to have suffered from an infection with the SARS virus. The inclusion of these cases, almost all asymptomatic, did not impact the total number of SARS fatalities. What happened to the case-fatality rate (CFR) following this reclassification? Question: What is the probability of surviving the second year of the study given that a person survived the first year? Question: Table not avb Question: What is the probability chance of surviving 3 years after diagnosis? The cumulative survival probability for all 3 years equals the product of the independent interval survival probabilities. In this example, 59% multiplied by 53% multiplied by 70.4% gives a cumulative survival probability of 22%. Question: Table not avb Question: Before reporting the results of this survival analysis, the investigators compared baseline characteristics of the 44 people who withdrew from the study before its end to those who had complete follow-up. This was done: Chapter 7-8 Question: Which of the following statements best describe efficacy? Question: A study is conducted for a pharmaceutical agent that has shown promise for reducing heart disease among women. In order to more fully test the agent, an additional study is done restricting the participants to … randomized to those who have a history of hypertension. Which of the following advantages cannot … claimed by the researchers? Question: A new drug treatment for cardiac thrombus claims to have a higher success rate than the current drug. A strong sign of the potential success is the lack of internal hemorrhaging starting 2 days after treatment. 168 patients who require treatment for cardiac thrombi are randomized after agreeing to participate in a trial of the new drug. The researchers were interested in whether the new drug reduced the need for blood transfusions due to internal hemorrhage compared to the current treatment. The following table summarizes the results of her study: What is the incidence of needing a blood transfusion in the group of persons who were randomized to the new drug treatment? Question: Same table info- What is the number of persons who died in hospital in the study? Question: Same table- What is the main advantage of the randomization of the 168 study participants to one of the two drug treatment groups? Question: The researchers interpret the findings to conclude that the new drug treatment is more likely to result in a blood transfusion and subsequent death. This statement is: Though the death rate among those receiving a transfusion cannot … directly compared with this table, the high rate of transfusion and subsequent death in the new drug treatment group strongly implies that the new drug treatment is more likely to result in these outcomes. Question: A randomized, double-blind clinical trial of a varicella vaccine observed an estimated incidence of 25% chickenpox episodes in persons receiving the vaccine, compared to 80% among persons receiving a placebo. The estimated efficacy of the vaccine is: Question: A multicenter double-blind randomized study was carried out to compare the effect of drug X with that of a placebo in patients surviving acute myocardial infarction (AMI). Treatment with the drug started 7 days after infarction in 1,884 patients, 52% of all persons who were evaluated for entry into the study. 945 participants were randomized to treatment with drug X while 939 were assigned to the placebo group. Patients were then followed for 12 months for reinfarction. There were 152 deaths in the placebo group and 98 in the group receiving drug X. After entry into the study, patients were first classified into three groups, those who had a previous AMI, those with a first AMI who were at high risk for other cardiovascular diseases such as congestive heart failure, and those with a first AMI who were at low risk for other cardiovascular diseases. Which term best describes the study design? Question: After assignment to treatment group, 77% of those in the placebo group were men, while 80% of those in the drug X group were men. Which statement is most likely to … true? Question: A preliminary analysis was conducted after 6 months and found that 87% of participants in the placebo group and 85% of those in the drug X group had taken more than 90% of their prescribed dosages. Which statement best describes this finding? Question: Which of the following statements best describes the reason for conducting the study as a double-blind trial? Question: The researchers conclude that treatment with drug X reduces mortality in patients who have had an AMI. The researchers are: Question: The following data come from a study of approaches to smoking cessation. Smokers who want to quit were randomized to one of four groups: control group C who received no intervention assistance, quitting guide group Q who received brochures about how to quit smoking, quitting guide and support group QS who received quitting brochures as well as social support brochures listing benefits of smoking cessation, and telephone support group T who received the brochures and a monthly phone call from a counselor. Participants received mailed surveys at 8, 16, and 24 months after randomization. The results after 2 years are in the table below. What is the overall quit rate after 2 years of follow-up? Question: same info- Which group had the least success in terms of quitting smoking? Question: same info- What is the main purpose of randomization in this study? [Show Less]

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