EPI Exam 2 Questions And Correct
Answers A+ Graded
Which of the following represents a sample of the population in which researchers
identify and enroll cases of disease as well as a sample of the source population giving
rise to the cases? - ANSWER Case-control study
High degree if validity in what type of study, stems mainly from the investigator's ability
to randomize subjects to either the treatment group or the comparison group and
thereby control for distortions produced by confounding variables? - ANSWER
Experimental study
Which kind of study assesses an association by using the population rather than the
individual as the unit of analysis? - ANSWER Ecological study
What is the major disadvantage of using which type of controls involves difficulty in
determining appropriate illnesses for inclusion? - ANWER Hospital and clinic controls
Which of the following is another term for the exposed group? - ANSWER index group
Observational studies take advantage of the fact that people expose themselves to
noxious or healthy substances through their personal habits. - ANSWER true
Which type of observational study examines one or more health effects/outcomes of
exposure to a single agent? - ANSWER cohort study
Which type of studies typically take a snapshot of a population at a single point in time
and therefore usually measures the disease prevalence, exposure prevalence, or
relationship between the two? - ANSWER Cross-sectional study
, A cohort study on the pattern of coffee drinking and anxiety was conducted on a
university campus. There were 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. What was the cumulative incidence of anxiety among coffee drinkers?
Which of the following correctly describes the interpretation of the relative risk? -
ANSWER Coffee drinkers are "x" times as likely to develop anxiety as compared to
non-coffee drinkers
Prospective cohort studies use historical data. - ANSWER false
Suppose there are 2,000 persons in a cohort of whom 800 are smokers and 1,200 are
non-smokers. Assume this entire cohort is followed for a total of 20 years during which
100 develop lung cancer, of whom 90 are smokers and 10 are not.
What is the incidence rate of lung cancer for non-smokers in this cohort per
1,000?-ANSWER 8.3 per 1,000
Suppose there is a cohort of 2,000 persons, 800 smokers and 1,200 non-smokers. This
entire cohort is followed for a period of 20 years and during this time 100 participants in
this study develop lung cancer, of which 90 are smokers and 10 are not.
What would be the relative risk of developing lung cancer for smokers to non-smokers in
this cohort? - ANSWER 13.5
Which of the following are characteristic features of Cohort studies (Choose all that
apply):
The groups being compared differ in their exposure status
It is essential that follow up is complete in ALL subjects.
Retrospectively or prospectively the investigators identify a cohort of subjects who
initially did not have the disease or outcome of interest.
Investigators measure and compare the incidence of disease (or some outcome) among
different exposure groups. - ANSWER -The groups being compared differ in their
exposure status
Answers A+ Graded
Which of the following represents a sample of the population in which researchers
identify and enroll cases of disease as well as a sample of the source population giving
rise to the cases? - ANSWER Case-control study
High degree if validity in what type of study, stems mainly from the investigator's ability
to randomize subjects to either the treatment group or the comparison group and
thereby control for distortions produced by confounding variables? - ANSWER
Experimental study
Which kind of study assesses an association by using the population rather than the
individual as the unit of analysis? - ANSWER Ecological study
What is the major disadvantage of using which type of controls involves difficulty in
determining appropriate illnesses for inclusion? - ANWER Hospital and clinic controls
Which of the following is another term for the exposed group? - ANSWER index group
Observational studies take advantage of the fact that people expose themselves to
noxious or healthy substances through their personal habits. - ANSWER true
Which type of observational study examines one or more health effects/outcomes of
exposure to a single agent? - ANSWER cohort study
Which type of studies typically take a snapshot of a population at a single point in time
and therefore usually measures the disease prevalence, exposure prevalence, or
relationship between the two? - ANSWER Cross-sectional study
, A cohort study on the pattern of coffee drinking and anxiety was conducted on a
university campus. There were 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. What was the cumulative incidence of anxiety among coffee drinkers?
Which of the following correctly describes the interpretation of the relative risk? -
ANSWER Coffee drinkers are "x" times as likely to develop anxiety as compared to
non-coffee drinkers
Prospective cohort studies use historical data. - ANSWER false
Suppose there are 2,000 persons in a cohort of whom 800 are smokers and 1,200 are
non-smokers. Assume this entire cohort is followed for a total of 20 years during which
100 develop lung cancer, of whom 90 are smokers and 10 are not.
What is the incidence rate of lung cancer for non-smokers in this cohort per
1,000?-ANSWER 8.3 per 1,000
Suppose there is a cohort of 2,000 persons, 800 smokers and 1,200 non-smokers. This
entire cohort is followed for a period of 20 years and during this time 100 participants in
this study develop lung cancer, of which 90 are smokers and 10 are not.
What would be the relative risk of developing lung cancer for smokers to non-smokers in
this cohort? - ANSWER 13.5
Which of the following are characteristic features of Cohort studies (Choose all that
apply):
The groups being compared differ in their exposure status
It is essential that follow up is complete in ALL subjects.
Retrospectively or prospectively the investigators identify a cohort of subjects who
initially did not have the disease or outcome of interest.
Investigators measure and compare the incidence of disease (or some outcome) among
different exposure groups. - ANSWER -The groups being compared differ in their
exposure status
