EPIDEMIOLOGY END OF COURSE EXAM QUESTIONS AND
ANSWERS MARKED A+
✔✔True or False: The denominator of a risk is not fixed by the "at-risk" population size
at the beginning of a study observation period. - ✔✔False
✔✔In order to calculate a risk, which of the following steps must be taken?
A. determine the number of males and females in the study
B. define the at-risk study population
C. determine the number of new cases of the outcome under study
D. define a case definition for the health outcome under study
E. determine how many people in the study were exposure or unexposed to the
exposure under study - ✔✔B, C, D
✔✔The denominator of a rate is affected by which of the following?
A. study drop-outs
B. loss to follow-up
C. migration
D. births
E. deaths - ✔✔A, B, C, D, E
✔✔Which of the following are advantages of using a rate measure?
A. good for health outcomes or disease that are of long duration
B. good for health outcomes or diseases with long latent periods
C. can accommodate repeated events that affect the same study participant
D. suitable for a dynamic population
E. flexibility - ✔✔A, B, C, D, E
✔✔Which of the following measure(s) is/are able to capture the reality of a dynamic
population?
A. risk
B. odds
C. prevalence
D. rate - ✔✔D
✔✔If you are studying the rate of leukemia, which of the following events would affect a
participant's person-time?
A. death
B. being sick with influenza
C. participant goes out of town for a weekend
D. participant decides to no longer participate in the study
E. loss to follow-up - ✔✔A, D, E
, ✔✔If you are studying the rate of breast cancer, which of the following events would
affect a participant's person-time?
A. loss to follow up
B. participant decides to no longer participate in the study
C. death
D. patient undergoes a double mastectomy
E. diagnosis with uterine cancer - ✔✔A, B, C, D
✔✔If you are studying the rate of relapse for lung cancer after treatment, which of the
following events would affect a participant's person-time?
A. time period(s) when the patient is considered to have active lung cancer
B. time of initial diagnosis with lung cancer
C. participant decides to no longer participate in the study
D. time period(s) the patient is in remission from lung cancer - ✔✔A, C, D
✔✔Once the study population has been defined, the denominator of a risk is affected by
which of the following?
A. deaths
B. who is at risk of developing the health outcome
C. loss to follow-up
D. migration
E. births - ✔✔B
✔✔Which of the following are acceptable ways to express "person-time"?
A. person-months
B. person-minutes
C. person-days
D. person-years - ✔✔A, B, C, D
✔✔Which of the following measures is sometimes used because of its convenient
mathematical properties?
A. rate
B. risk
C. odds
D. prevalence - ✔✔C
✔✔True or False: It is always ethical to randomly have the investigator assign
exposures to study participants in experimental studies. - ✔✔False
✔✔Which study is best described in this statement: "A study where the effectiveness of
2 different diabetes drugs are compared." - ✔✔randomized control trial
ANSWERS MARKED A+
✔✔True or False: The denominator of a risk is not fixed by the "at-risk" population size
at the beginning of a study observation period. - ✔✔False
✔✔In order to calculate a risk, which of the following steps must be taken?
A. determine the number of males and females in the study
B. define the at-risk study population
C. determine the number of new cases of the outcome under study
D. define a case definition for the health outcome under study
E. determine how many people in the study were exposure or unexposed to the
exposure under study - ✔✔B, C, D
✔✔The denominator of a rate is affected by which of the following?
A. study drop-outs
B. loss to follow-up
C. migration
D. births
E. deaths - ✔✔A, B, C, D, E
✔✔Which of the following are advantages of using a rate measure?
A. good for health outcomes or disease that are of long duration
B. good for health outcomes or diseases with long latent periods
C. can accommodate repeated events that affect the same study participant
D. suitable for a dynamic population
E. flexibility - ✔✔A, B, C, D, E
✔✔Which of the following measure(s) is/are able to capture the reality of a dynamic
population?
A. risk
B. odds
C. prevalence
D. rate - ✔✔D
✔✔If you are studying the rate of leukemia, which of the following events would affect a
participant's person-time?
A. death
B. being sick with influenza
C. participant goes out of town for a weekend
D. participant decides to no longer participate in the study
E. loss to follow-up - ✔✔A, D, E
, ✔✔If you are studying the rate of breast cancer, which of the following events would
affect a participant's person-time?
A. loss to follow up
B. participant decides to no longer participate in the study
C. death
D. patient undergoes a double mastectomy
E. diagnosis with uterine cancer - ✔✔A, B, C, D
✔✔If you are studying the rate of relapse for lung cancer after treatment, which of the
following events would affect a participant's person-time?
A. time period(s) when the patient is considered to have active lung cancer
B. time of initial diagnosis with lung cancer
C. participant decides to no longer participate in the study
D. time period(s) the patient is in remission from lung cancer - ✔✔A, C, D
✔✔Once the study population has been defined, the denominator of a risk is affected by
which of the following?
A. deaths
B. who is at risk of developing the health outcome
C. loss to follow-up
D. migration
E. births - ✔✔B
✔✔Which of the following are acceptable ways to express "person-time"?
A. person-months
B. person-minutes
C. person-days
D. person-years - ✔✔A, B, C, D
✔✔Which of the following measures is sometimes used because of its convenient
mathematical properties?
A. rate
B. risk
C. odds
D. prevalence - ✔✔C
✔✔True or False: It is always ethical to randomly have the investigator assign
exposures to study participants in experimental studies. - ✔✔False
✔✔Which study is best described in this statement: "A study where the effectiveness of
2 different diabetes drugs are compared." - ✔✔randomized control trial
