BIOSTATISTICS||VERIFIED QUESTIONS
AND ANSWERS||GURANTEE PASS
Subjects serve as their own controls in which of the following research design?
A) factorial design
B) parallel design
C) cross-over design
D) randomized control trial
E) case-control study
Ans: cross-over design
The most effective method of controlling extraneous variables is by:
A) analysis of covariance
B)bmatching
C) randomization
D) use control group
E) none of the above
Ans: randomization
A study is internally valid if:
A) a repeated-measures design was used
B) a causal relationship is confirmed
C) an experimental design was used
D) all alternative explanations of the results can be ruled out
,E) it can be generalized to the population
Ans: all alternative explanations of the results can be ruled out
The use of inferential statistics permits the researcher to:
A) generalize to a population based on information gathered from a sample
B) interpret descriptive statistics
C) describe information obtained from empirical observation
D) repeat the null hypothesis
Select a level of significance
Ans: generalize to a population based on information gathered from a sample
A study was conducted to evaluate an antibiotic in the treatment of possible bacteremia. Five
hundred children with fever but no focal infection were randomly assigned to the antibiotic or
to a placebo. All patients were re-evaluated after 48 hours. The design used in this study is best
described as a:
A) randomized clinical trial
B) placebo-controlled trial
C) controlled clinical trial
D) cohort study
Ans: randomized clinical trial
A study is conducted to compare the efficacy of two medications (drug a and drug b) for the
treatment of hypertension. One hundred patients are enrolled in the study (50 receiving drug a
and 50 receiving drug b). Which of the following terms best describes patients receiving the
study medications?
A) population
B) sample
C) experimental group
D) control group
,E) none of the above
Ans: sample
Which of the following research designs would be the most optimal in terms of controlling the
study and producing valid results for a clinical trial comparing two drugs?
A) prospective, randomized, double-blind parallel study
Prospective experimental with historical control, open-label, comparative study
B) prospective experimental with historical control, open-label, comparative study
C) observational, double-blind parallel study
D) retrospective, parallel, longitudinal, open-label study
E) a and c
Ans: prospective, randomized, double-blind parallel study
Patients may alter their behavior when they know they are being observed under study
conditions. Which of the following terms best describes this phenomenon?
A) contamination bias
B) selection bias
C) volunteer bias
D) attention bias (hawthorne effect)
E) admission rate bias (berkson's paradox)
Ans: attention bias (hawthorne effect)
Which of the following is true with respect to the term "random chance?"
A) outcomes of clinical trials may be affected by random chance
B) statistical tests help to determine the effect of random chance on the study outcomes
C) random chance is also known as "systematic variation"
D) a and b
E) all of the above
, Ans: a and b
A study is conducted to determine the efficacy of 2 drugs in preventing seasickness.
Measurements are taken to assess the following: no seasickness, mild seasickness, or severe
seasickness. Which of the following data types best describes these measurements?
A) nominal
B) ordinal
C) interval
D) ratio
E) integer
Ans: ordinal
Which of the following best describes the function of the inclusion criteria for a study?
A) ensures patient safety
B) describes the characteristics of the sample
C) is important in evaluating the external validity of the study
D) b and c
E) none of the above
Ans: b and c
A study is conducted to determine the effect of vitamin c tablets on mortality. After the study is
completed, the data indicate that patients taking vitamin c tablets had a decrease in mortality.
However, the study design did not control for the effects of dietary vitamin c. Which of the
following terms best describes the role of dietary vitamin c in this study?
A) independent variable
B) dependent variable
C) confounding variable
D) control variable
AND ANSWERS||GURANTEE PASS
Subjects serve as their own controls in which of the following research design?
A) factorial design
B) parallel design
C) cross-over design
D) randomized control trial
E) case-control study
Ans: cross-over design
The most effective method of controlling extraneous variables is by:
A) analysis of covariance
B)bmatching
C) randomization
D) use control group
E) none of the above
Ans: randomization
A study is internally valid if:
A) a repeated-measures design was used
B) a causal relationship is confirmed
C) an experimental design was used
D) all alternative explanations of the results can be ruled out
,E) it can be generalized to the population
Ans: all alternative explanations of the results can be ruled out
The use of inferential statistics permits the researcher to:
A) generalize to a population based on information gathered from a sample
B) interpret descriptive statistics
C) describe information obtained from empirical observation
D) repeat the null hypothesis
Select a level of significance
Ans: generalize to a population based on information gathered from a sample
A study was conducted to evaluate an antibiotic in the treatment of possible bacteremia. Five
hundred children with fever but no focal infection were randomly assigned to the antibiotic or
to a placebo. All patients were re-evaluated after 48 hours. The design used in this study is best
described as a:
A) randomized clinical trial
B) placebo-controlled trial
C) controlled clinical trial
D) cohort study
Ans: randomized clinical trial
A study is conducted to compare the efficacy of two medications (drug a and drug b) for the
treatment of hypertension. One hundred patients are enrolled in the study (50 receiving drug a
and 50 receiving drug b). Which of the following terms best describes patients receiving the
study medications?
A) population
B) sample
C) experimental group
D) control group
,E) none of the above
Ans: sample
Which of the following research designs would be the most optimal in terms of controlling the
study and producing valid results for a clinical trial comparing two drugs?
A) prospective, randomized, double-blind parallel study
Prospective experimental with historical control, open-label, comparative study
B) prospective experimental with historical control, open-label, comparative study
C) observational, double-blind parallel study
D) retrospective, parallel, longitudinal, open-label study
E) a and c
Ans: prospective, randomized, double-blind parallel study
Patients may alter their behavior when they know they are being observed under study
conditions. Which of the following terms best describes this phenomenon?
A) contamination bias
B) selection bias
C) volunteer bias
D) attention bias (hawthorne effect)
E) admission rate bias (berkson's paradox)
Ans: attention bias (hawthorne effect)
Which of the following is true with respect to the term "random chance?"
A) outcomes of clinical trials may be affected by random chance
B) statistical tests help to determine the effect of random chance on the study outcomes
C) random chance is also known as "systematic variation"
D) a and b
E) all of the above
, Ans: a and b
A study is conducted to determine the efficacy of 2 drugs in preventing seasickness.
Measurements are taken to assess the following: no seasickness, mild seasickness, or severe
seasickness. Which of the following data types best describes these measurements?
A) nominal
B) ordinal
C) interval
D) ratio
E) integer
Ans: ordinal
Which of the following best describes the function of the inclusion criteria for a study?
A) ensures patient safety
B) describes the characteristics of the sample
C) is important in evaluating the external validity of the study
D) b and c
E) none of the above
Ans: b and c
A study is conducted to determine the effect of vitamin c tablets on mortality. After the study is
completed, the data indicate that patients taking vitamin c tablets had a decrease in mortality.
However, the study design did not control for the effects of dietary vitamin c. Which of the
following terms best describes the role of dietary vitamin c in this study?
A) independent variable
B) dependent variable
C) confounding variable
D) control variable
