NR 503 Midterm Exam
Question 1
Which of the following statements best describe efficacy?
• It is an estimate of the benefit of treatment under ideal conditions
• It is an estimate of the reduction of disease in treated groups
Question 2
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 r&omized
to those who have a history of hypertension. Which of the following advantages cannot be claimed by the
researchers?
• The generalizability of the study is increased
Question 3
What is the main advantage of the r&omization of the 168 study participants to one of the two drugtreatment groups?
• Reduces the potential for selection bias in allocation of treatment group
Question 4
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 congestiveheart failure, & those
with a first AMI who were at low risk for other cardiovascular diseases. Which term best describes the study
design?
• R&omized clinical trial with stratified r&omization
Question 5
After assignment to treatment group, 77% of those in the placebo group were men, while 80% ofthose in the drug
X group were men. Which statement is most likely to be true?
• R&omization was successful since the investigators did not alter the selection of participants in
either group in order to ensure equal percentages of men
Question 6
A preliminary analysis was conducted after 6 months & found that 87% of participants in the placebo
, group & 85% of those in the drug X group had taken more than 90% of their prescribed dosages.Which
statement best describes this finding?
• The characteristics of patients who failed to comply with the treatment dosages should be
assessed as they may differ from those who complied
Question 7
Which of the following statements best describes the reason for conducting the study as a double-blind trial?
• Double blinding ensures that potential biases regarding selection, follow-up, & analysis can be
reduced
Question 8
A multicenter double-blind r&omized 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 r&omized 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 & 98 in the group receiving drug X.
The researchers conclude that treatment with drug X reduces mortality in patients who have had an AMI. The
researchers are:
• Correct because the rate of death is decreased in the drug X group
Question 9
The following data come from a study of approaches to smoking cessation. Smokers who want to quitwere
r&omized 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 & support group QS who received quitting
brochures as well as social support brochures listing benefits of smoking cessation, & telephone support group T
who received the brochures & a monthly phone call from a counselor. Participants received mailed surveys at 8,
16, & 24 months after r&omization. The results after 2 years are in the table below. Which group had the least
success in terms of quitting smoking?
• Group QS
Question 10
Question 1
Which of the following statements best describe efficacy?
• It is an estimate of the benefit of treatment under ideal conditions
• It is an estimate of the reduction of disease in treated groups
Question 2
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 r&omized
to those who have a history of hypertension. Which of the following advantages cannot be claimed by the
researchers?
• The generalizability of the study is increased
Question 3
What is the main advantage of the r&omization of the 168 study participants to one of the two drugtreatment groups?
• Reduces the potential for selection bias in allocation of treatment group
Question 4
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 congestiveheart failure, & those
with a first AMI who were at low risk for other cardiovascular diseases. Which term best describes the study
design?
• R&omized clinical trial with stratified r&omization
Question 5
After assignment to treatment group, 77% of those in the placebo group were men, while 80% ofthose in the drug
X group were men. Which statement is most likely to be true?
• R&omization was successful since the investigators did not alter the selection of participants in
either group in order to ensure equal percentages of men
Question 6
A preliminary analysis was conducted after 6 months & found that 87% of participants in the placebo
, group & 85% of those in the drug X group had taken more than 90% of their prescribed dosages.Which
statement best describes this finding?
• The characteristics of patients who failed to comply with the treatment dosages should be
assessed as they may differ from those who complied
Question 7
Which of the following statements best describes the reason for conducting the study as a double-blind trial?
• Double blinding ensures that potential biases regarding selection, follow-up, & analysis can be
reduced
Question 8
A multicenter double-blind r&omized 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 r&omized 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 & 98 in the group receiving drug X.
The researchers conclude that treatment with drug X reduces mortality in patients who have had an AMI. The
researchers are:
• Correct because the rate of death is decreased in the drug X group
Question 9
The following data come from a study of approaches to smoking cessation. Smokers who want to quitwere
r&omized 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 & support group QS who received quitting
brochures as well as social support brochures listing benefits of smoking cessation, & telephone support group T
who received the brochures & a monthly phone call from a counselor. Participants received mailed surveys at 8,
16, & 24 months after r&omization. The results after 2 years are in the table below. Which group had the least
success in terms of quitting smoking?
• Group QS
Question 10
