PUBH 6035 FINAL EXAM 2025-2026 WINTER QTR. (100%
GENUINE QUESTIONS AND ANSWERS)
QUESTION 1
1. If the incidence rate of a very serious disease is 25/100,000 person-years and the
prevalence of this disease in the population is 75/100,000, what is the average
survival time of individuals who contract this disease?
a 1 year
.
b 3 years
.
c3
. months
d4
. months
5 points
QUESTION 2
1. A report of a clinical trial of a new drug versus a placebo noted that the new drug gave
a higher proportion of successes than did the placebo (70% versus 40%). The report
ended with the statement that the p value associated with this finding was
equal to 0.05. This means that 5 out of 100 patients did not benefit from the new drug.
5 points
QUESTION 3
1. When a new prevention measure for a disease is developed, both the incidence and
prevalence of the disease will decrease over the long term.
5 points
QUESTION 4
1. What can randomization do that no other method to control confounding can do?
a It can control for known confounders
.
b It can assure there is no bias in the study results
.
c It can automatically assess effect modification
.
d It can prevent self-selection of subjects into the groups
, . being compared
5 points
QUESTION 6
1. A cohort study of coffee drinking and anxiety was conducted at a university campus.
There were a total of 30,000 freshmen who participated. 10,000 were coffee drinkers
and 20,000 were not. Of the coffee drinkers, 500 developed anxiety during the 4 year
follow-up period. Of the non-coffee drinkers, 200 developed anxiety during the same
time period. Assume that no one in the population died or was lost during the follow-
up period. Calculate the risk difference using the given data. The numeric value of the
risk difference is…
a
6.0 %
.
b
4.0 %
.
c
5.0 %
.
d None of the
. above
5 points
QUESTION 7
1. Consider the situation in a cohort study where the crude risk ratio is 2.5. The data are
then divided into two groups. In the first group the group-specific risk ratio is 1.0, and
the second group’s risk ratio is 4.0. Which of the following is present?
a Positive confounding
.
b Negative confounding
.
c No effect modification or
. confounding
d Effect modification, confounding
. irrelevant
GENUINE QUESTIONS AND ANSWERS)
QUESTION 1
1. If the incidence rate of a very serious disease is 25/100,000 person-years and the
prevalence of this disease in the population is 75/100,000, what is the average
survival time of individuals who contract this disease?
a 1 year
.
b 3 years
.
c3
. months
d4
. months
5 points
QUESTION 2
1. A report of a clinical trial of a new drug versus a placebo noted that the new drug gave
a higher proportion of successes than did the placebo (70% versus 40%). The report
ended with the statement that the p value associated with this finding was
equal to 0.05. This means that 5 out of 100 patients did not benefit from the new drug.
5 points
QUESTION 3
1. When a new prevention measure for a disease is developed, both the incidence and
prevalence of the disease will decrease over the long term.
5 points
QUESTION 4
1. What can randomization do that no other method to control confounding can do?
a It can control for known confounders
.
b It can assure there is no bias in the study results
.
c It can automatically assess effect modification
.
d It can prevent self-selection of subjects into the groups
, . being compared
5 points
QUESTION 6
1. A cohort study of coffee drinking and anxiety was conducted at a university campus.
There were a total of 30,000 freshmen who participated. 10,000 were coffee drinkers
and 20,000 were not. Of the coffee drinkers, 500 developed anxiety during the 4 year
follow-up period. Of the non-coffee drinkers, 200 developed anxiety during the same
time period. Assume that no one in the population died or was lost during the follow-
up period. Calculate the risk difference using the given data. The numeric value of the
risk difference is…
a
6.0 %
.
b
4.0 %
.
c
5.0 %
.
d None of the
. above
5 points
QUESTION 7
1. Consider the situation in a cohort study where the crude risk ratio is 2.5. The data are
then divided into two groups. In the first group the group-specific risk ratio is 1.0, and
the second group’s risk ratio is 4.0. Which of the following is present?
a Positive confounding
.
b Negative confounding
.
c No effect modification or
. confounding
d Effect modification, confounding
. irrelevant
