NR503 MIDTERM ACTUAL EXAM

NR503 MIDTERM ACTUAL EXAM

QUESTIONS AND ANSWERS

The nurse practitioner is reviewing a recent study that utilizes analytic epidemiology by means of a cohort study design. The cohort study design informs the practitioner about which of the following - ANS✅Outcomes that develop from an exposure A group of providers have implemented population-based intervention and are now assessing the efficacy of the intervention. Which of the following would be an example of a population based outcome? - ANS✅Decreased mortality rate compared to previous year Appraisal of research publications is critical as providers assess for relevance to population health. Which of the following items should be considered during the appraisal process? Select all that apply. - ANS✅Outcome measure, Transparency, Internal Validity What is being compared in a cohort study design? - ANS✅The incidence of a disease between exposed and non-exposed individuals Analytic epidemiology is best described as: - ANS✅Studies that investigate origins and casuals' factors of health-related events You are part of a research group investigating association between exposure and disease. Which

study design is a best fit for this type of study: - ANS✅Case-Control Study

The provider is concerned about what appears to be an increase in the mortality rate for their community. Mortality is an example of which of the following: - ANS✅Vital statistic An example of a tertiary prevention measure for chronic obstructive pulmonary disease is: - ANS✅Pulmonary Rehabilitation Which of the following statements best describe efficacy? - ANS✅It is an estimate of the benefit of treatment under ideal conditions It is an estimate of the reduction of disease in treated groups

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 be randomized to those who have a history of hypertension. Which of the following advantages cannot be claimed by the researchers? - ANS✅The generalizability of the study is increased What is the main advantage of the randomization of the 168 study participants to one of the two drug treatment groups? - ANS✅Reduces selection bias 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? - ANS✅Randomized clinical trial with stratified randomization 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 be true? - ANS✅Randomization was successful since the investigators did not alter the selection of participants in either group in order to ensure equal percentages of men 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? - ANS✅The characteristics of patients who failed to comply with the treatment dosages should be assessed as they may differ from those who complied Which of the following statements best describes the reason for conducting the study as a double-blind trial? - ANS✅Double blinding ensures that potential biases regarding selection, follow-up, and analysis can be reduced 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 ..... 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. Which group had the least success in terms of quitting smoking? - ANS✅Group QS

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 main purpose of randomization in this study? - ANS✅To avoid assigning more persons who have tried and failed to quit in the past to the control group 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?

• ANS✅The total number of false positives found by both tests is decreased if Test B is given first

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.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? - ANS✅Sensitivity will decrease 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 - ANS✅Overall percent agreement calculated for both readers may conceal significant disagreements regarding positive tests A researcher is interested in the etiology of cervical cancer among women between 18 and 35 years of age. Her hypothesis concerns the influence of sexually transmitted diseases such as human papilloma virus (HPV) and subsequent development of cancer. What is the best study approach to address this hypothesis? - ANS✅Case-control study of women 18 to 35 years of age identified with cervical cancer in the hospital (cases) compared to women admitted for other diseases (control) Suppose that one third of all cervical cancer cases were smokers as were one third of all controls and smoking status is independent of HPV infection. Is smoking a potential confounder in this study? - ANS✅No, the chance of being a smoker among women with cervical cancer is the same as that of being a smoker among women without cervical cancer

A case-control study was conducted to determine if an association exists between workers in uranium mines and loss of fertility due to reduced sperm count. A group of 200 men with low sperm count were identified from clinics located in areas with uranium mines. Each selected case was matched with a randomly selected male control on the following factors: race, age, area of residence, and smoking status. What is the purpose of matching? - ANS✅Previous studies have shown that there are racial differences in low sperm count 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. Not all 135,000 cases of TB were contracted during 2005. Which of the following statements is true? - ANS✅Since the duration of TB can be longer than 1 year, neither disease incidence nor prevalence can be validly estimated by mortality indicators.Which of the following statements pertains to relative survival? - ANS✅Relative survival is close to observed survival rate when there are few competing causes of death. This occurs primarily in younger age groups who are less likely to experience mortality events compared to older age groups.Before reporting the results of this survival analysis, the investigators compared baseline characteristics of the 38 people who withdrew from the study before its end to those who had complete follow-up. This was done for which of the following reasons: - ANS✅To check whether those who remained in the study represent the total study population Which of the following is a key assumption involved in the use of life-table analysis? - ANS✅Life- table analysis depends upon a consistent rate of survival during all periods of the study. Changes in the rate of survival may be due to external influences that are operating at later times on only a portion of the initial population. Since those who have died earlier in the study period will not experience these external influences, the comparison between periods is rendered invalid.When incidence density sampling is used in a case-control study, which of the following is an important consideration? - ANS✅A subject selected as a control may later be selected as a case A recent prospective study on baldness and coronary heart disease (CHD) concluded that there was no association between the two, despite earlier cross-sectional studies which showed that baldness was associated with CHD when the two were determined at the same time in men.