Biostats Midterm UPDATED ACTUAL
Exam Questions and CORRECT Answers
In a clinical study, investigating the efficacy of topical analgesia prior to venepuncture, 35
volunteer subjects each acted as their own controls. In other words, there was only one group of
subjects. The subjects were given treatment, EMLA or placebo on one arm. The outcome
measure was the time taken for the area of application on the arm to go numb. Randomization
was employed in this study. (Nott et al 1996)
Does this study meet the NIH definition of a clinical trial?
-Yes
-No: only one group means no randomization
-No: outcomes needed to be measured 3x
-No: only one group means no control - CORRECT ANSWER - Yes
In a clinical study, investigating the efficacy of topical analgesia prior to venepuncture, 35
volunteer subjects each acted as their own controls. They were given treatment, EMLA or
placebo on one arm. The outcome measure was the time taken for the area of application on the
arm to go numb. This was then repeated for placebo or treatment on the other arm.
Randomization was employed in this study. (Nott et al 1996)
Which of the following supports the fact that the randomization was indeed employed?
-Both are correct
-choice of treatment for each arm was random- equal chance the arm was treatment or placebo,
removing bias of outcome handedness
-each arm was assessed separately- order of assessment was random, removing bias of outcome
assessment - CORRECT ANSWER - both are correct
what is the opposite of open-label trials?
-controlled
, -intervention
-blinded
-randomized - CORRECT ANSWER - blinded trials
what studies are longitudinal?
-case-control
-prospective
-retrospective
-clinical
-randomized controlled trials - CORRECT ANSWER - case-control, pro- & retrospective,
clinical, RCTs
is it possible to design a clinical trial in which the exposure is handedness and the outcome is
long term mortality? - CORRECT ANSWER - no, not able to randomly assign handedness
In a study conducted by Gardosi, et al (1989) mentioned in the slides on birth position in labor,
14% of women did not use the position to which they had been allocated.
Why is it important to perform an intention-to-treat analysis?
-it is an RCT
-randomization would be upset if an as-treated analysis were conducted, creating a possible
imbalance between groups @ baseline
-women provided consent
-this wasn't a cohort study - CORRECT ANSWER - -because the randomization would be
upset if an as-treated analysis were conducted, creating a possible imbalance between groups @
baseline
Exam Questions and CORRECT Answers
In a clinical study, investigating the efficacy of topical analgesia prior to venepuncture, 35
volunteer subjects each acted as their own controls. In other words, there was only one group of
subjects. The subjects were given treatment, EMLA or placebo on one arm. The outcome
measure was the time taken for the area of application on the arm to go numb. Randomization
was employed in this study. (Nott et al 1996)
Does this study meet the NIH definition of a clinical trial?
-Yes
-No: only one group means no randomization
-No: outcomes needed to be measured 3x
-No: only one group means no control - CORRECT ANSWER - Yes
In a clinical study, investigating the efficacy of topical analgesia prior to venepuncture, 35
volunteer subjects each acted as their own controls. They were given treatment, EMLA or
placebo on one arm. The outcome measure was the time taken for the area of application on the
arm to go numb. This was then repeated for placebo or treatment on the other arm.
Randomization was employed in this study. (Nott et al 1996)
Which of the following supports the fact that the randomization was indeed employed?
-Both are correct
-choice of treatment for each arm was random- equal chance the arm was treatment or placebo,
removing bias of outcome handedness
-each arm was assessed separately- order of assessment was random, removing bias of outcome
assessment - CORRECT ANSWER - both are correct
what is the opposite of open-label trials?
-controlled
, -intervention
-blinded
-randomized - CORRECT ANSWER - blinded trials
what studies are longitudinal?
-case-control
-prospective
-retrospective
-clinical
-randomized controlled trials - CORRECT ANSWER - case-control, pro- & retrospective,
clinical, RCTs
is it possible to design a clinical trial in which the exposure is handedness and the outcome is
long term mortality? - CORRECT ANSWER - no, not able to randomly assign handedness
In a study conducted by Gardosi, et al (1989) mentioned in the slides on birth position in labor,
14% of women did not use the position to which they had been allocated.
Why is it important to perform an intention-to-treat analysis?
-it is an RCT
-randomization would be upset if an as-treated analysis were conducted, creating a possible
imbalance between groups @ baseline
-women provided consent
-this wasn't a cohort study - CORRECT ANSWER - -because the randomization would be
upset if an as-treated analysis were conducted, creating a possible imbalance between groups @
baseline
