Master of Public Health (MPH)
Program Comprehensive Test Bank
TABLE OF CONTENTS
Epidemiology - Questions 1-25
Biostatistics - Questions 26-50
Environmental Health Sciences - Questions 51-65
Health Policy and Management - Questions 66-80
Social and Behavioral Sciences - Questions 81-100
EPIDEMIOLOGY
Q1. A researcher conducts a study in which 500 factory workers exposed to a chemical solvent are
followed for 10 years and compared with 500 unexposed workers from the same factory. Which
study design is being used?
Cohort study
Case-control study
Cross-sectional study
Randomized controlled trial
Correct Answer: Cohort study
Rationale: A cohort study follows exposed and unexposed groups forward in time and
compares disease incidence. Case-control studies start with outcome status and look backward at
exposure. Cross-sectional studies measure exposure and outcome at the same time. Randomized
controlled trials assign exposure by randomization.
Q2. A researcher identifies 200 patients with lung cancer and 400 controls without lung cancer and
compares their past smoking histories. Which study design is being used?
Case-control study
Cohort study
Cross-sectional study
,Ecologic study
Correct Answer: Case-control study
Rationale: A case-control study selects participants by outcome status (cases and controls) and
looks backward at past exposures. Cohort studies follow exposure groups forward. Cross-sectional
studies measure exposure and outcome simultaneously. Ecologic studies use group-level data.
Q3. A researcher surveys 1,000 adults in a single visit and measures both their physical activity levels
and their blood pressure. Which study design is being used?
Cross-sectional study
Cohort study
Case-control study
Clinical trial
Correct Answer: Cross-sectional study
Rationale: A cross-sectional study measures exposure and outcome at the same point in time
in a defined population. Cohort studies follow groups over time. Case-control studies select by
outcome. Clinical trials involve intervention.
Q4. A study reports that the incidence of tuberculosis in Country A is 45 per 100,000 person-years.
Which measure of disease frequency is being reported?
Incidence rate
Prevalence
Attack rate
Case fatality rate
Correct Answer: Incidence rate
Rationale: Incidence rate measures new cases per unit of person-time. Prevalence measures
existing cases at a point or period. Attack rate is used in outbreak settings. Case fatality rate
measures deaths among cases.
Q5. A survey finds that 12 percent of adults in a city currently have diabetes. Which measure is being
reported?
Point prevalence
Incidence rate
Attack rate
,Mortality rate
Correct Answer: Point prevalence
Rationale: Point prevalence is the proportion of a population with a condition at a specific
time. Incidence rate measures new cases. Attack rate is used in outbreaks. Mortality rate measures
deaths in a population.
Q6. In an outbreak of foodborne illness at a wedding, 60 of the 100 people who ate the chicken
became ill, while 10 of the 100 who did not eat the chicken became ill. What is the attack rate among
those who ate the chicken?
60 percent
10 percent
50 percent
100 percent
Correct Answer: 60 percent
Rationale: Attack rate is the proportion of exposed persons who become ill. 60 out of 100
equals 60 percent. The comparison group rate is 10 percent. The overall attack rate would be
calculated differently. The relative risk would require comparing the two attack rates.
Q7. A study finds that the risk of myocardial infarction among smokers is 4 times that of non-
smokers. What measure is being reported?
Relative risk
Attributable risk
Odds ratio
Prevalence ratio
Correct Answer: Relative risk
Rationale: Relative risk is the ratio of disease risk in exposed compared with unexposed.
Attributable risk is the difference in risk. Odds ratio is used in case-control studies. Prevalence ratio
compares prevalence between groups.
Q8. A case-control study reports an odds ratio of 3.2 for the association between a rare exposure and
a disease. Which is the best interpretation?
Exposed individuals had 3.2 times the odds of disease compared with unexposed
Exposed individuals had 3.2 times the risk of disease compared with unexposed
, The disease occurred in 3.2 percent of the exposed group
The exposure caused 32 percent of cases
Correct Answer: Exposed individuals had 3.2 times the odds of disease compared with unexposed
Rationale: An odds ratio expresses the odds of exposure among cases compared with controls.
It is not a direct measure of risk. It does not represent a percentage of cases. Causation is not
established by the ratio alone.
Q9. A study finds an attributable risk of 25 per 1,000 among exposed persons. What does this mean?
25 cases per 1,000 exposed are attributable to the exposure
25 percent of the exposed population will develop the disease
25 percent of cases occur in the exposed group
The relative risk is 25
Correct Answer: 25 cases per 1,000 exposed are attributable to the exposure
Rationale: Attributable risk is the difference in incidence between exposed and unexposed,
representing excess cases due to exposure. It is not a percentage of the whole population. It is not
the proportion of cases. It is not the relative risk.
Q10. Which measure best describes the proportion of disease in the total population that could be
prevented if the exposure were eliminated?
Population attributable risk
Relative risk
Odds ratio
Incidence rate
Correct Answer: Population attributable risk
Rationale: Population attributable risk estimates the proportion of disease in the population
that is due to the exposure. Relative risk compares risk between exposed and unexposed. Odds ratio
is used in case-control studies. Incidence rate is a frequency measure.
Q11. In a screening program, a new test is evaluated against a gold standard. Of 100 people with
disease, 90 test positive. Of 200 without disease, 180 test negative. What is the sensitivity of the
test?
90 percent
80 percent
Program Comprehensive Test Bank
TABLE OF CONTENTS
Epidemiology - Questions 1-25
Biostatistics - Questions 26-50
Environmental Health Sciences - Questions 51-65
Health Policy and Management - Questions 66-80
Social and Behavioral Sciences - Questions 81-100
EPIDEMIOLOGY
Q1. A researcher conducts a study in which 500 factory workers exposed to a chemical solvent are
followed for 10 years and compared with 500 unexposed workers from the same factory. Which
study design is being used?
Cohort study
Case-control study
Cross-sectional study
Randomized controlled trial
Correct Answer: Cohort study
Rationale: A cohort study follows exposed and unexposed groups forward in time and
compares disease incidence. Case-control studies start with outcome status and look backward at
exposure. Cross-sectional studies measure exposure and outcome at the same time. Randomized
controlled trials assign exposure by randomization.
Q2. A researcher identifies 200 patients with lung cancer and 400 controls without lung cancer and
compares their past smoking histories. Which study design is being used?
Case-control study
Cohort study
Cross-sectional study
,Ecologic study
Correct Answer: Case-control study
Rationale: A case-control study selects participants by outcome status (cases and controls) and
looks backward at past exposures. Cohort studies follow exposure groups forward. Cross-sectional
studies measure exposure and outcome simultaneously. Ecologic studies use group-level data.
Q3. A researcher surveys 1,000 adults in a single visit and measures both their physical activity levels
and their blood pressure. Which study design is being used?
Cross-sectional study
Cohort study
Case-control study
Clinical trial
Correct Answer: Cross-sectional study
Rationale: A cross-sectional study measures exposure and outcome at the same point in time
in a defined population. Cohort studies follow groups over time. Case-control studies select by
outcome. Clinical trials involve intervention.
Q4. A study reports that the incidence of tuberculosis in Country A is 45 per 100,000 person-years.
Which measure of disease frequency is being reported?
Incidence rate
Prevalence
Attack rate
Case fatality rate
Correct Answer: Incidence rate
Rationale: Incidence rate measures new cases per unit of person-time. Prevalence measures
existing cases at a point or period. Attack rate is used in outbreak settings. Case fatality rate
measures deaths among cases.
Q5. A survey finds that 12 percent of adults in a city currently have diabetes. Which measure is being
reported?
Point prevalence
Incidence rate
Attack rate
,Mortality rate
Correct Answer: Point prevalence
Rationale: Point prevalence is the proportion of a population with a condition at a specific
time. Incidence rate measures new cases. Attack rate is used in outbreaks. Mortality rate measures
deaths in a population.
Q6. In an outbreak of foodborne illness at a wedding, 60 of the 100 people who ate the chicken
became ill, while 10 of the 100 who did not eat the chicken became ill. What is the attack rate among
those who ate the chicken?
60 percent
10 percent
50 percent
100 percent
Correct Answer: 60 percent
Rationale: Attack rate is the proportion of exposed persons who become ill. 60 out of 100
equals 60 percent. The comparison group rate is 10 percent. The overall attack rate would be
calculated differently. The relative risk would require comparing the two attack rates.
Q7. A study finds that the risk of myocardial infarction among smokers is 4 times that of non-
smokers. What measure is being reported?
Relative risk
Attributable risk
Odds ratio
Prevalence ratio
Correct Answer: Relative risk
Rationale: Relative risk is the ratio of disease risk in exposed compared with unexposed.
Attributable risk is the difference in risk. Odds ratio is used in case-control studies. Prevalence ratio
compares prevalence between groups.
Q8. A case-control study reports an odds ratio of 3.2 for the association between a rare exposure and
a disease. Which is the best interpretation?
Exposed individuals had 3.2 times the odds of disease compared with unexposed
Exposed individuals had 3.2 times the risk of disease compared with unexposed
, The disease occurred in 3.2 percent of the exposed group
The exposure caused 32 percent of cases
Correct Answer: Exposed individuals had 3.2 times the odds of disease compared with unexposed
Rationale: An odds ratio expresses the odds of exposure among cases compared with controls.
It is not a direct measure of risk. It does not represent a percentage of cases. Causation is not
established by the ratio alone.
Q9. A study finds an attributable risk of 25 per 1,000 among exposed persons. What does this mean?
25 cases per 1,000 exposed are attributable to the exposure
25 percent of the exposed population will develop the disease
25 percent of cases occur in the exposed group
The relative risk is 25
Correct Answer: 25 cases per 1,000 exposed are attributable to the exposure
Rationale: Attributable risk is the difference in incidence between exposed and unexposed,
representing excess cases due to exposure. It is not a percentage of the whole population. It is not
the proportion of cases. It is not the relative risk.
Q10. Which measure best describes the proportion of disease in the total population that could be
prevented if the exposure were eliminated?
Population attributable risk
Relative risk
Odds ratio
Incidence rate
Correct Answer: Population attributable risk
Rationale: Population attributable risk estimates the proportion of disease in the population
that is due to the exposure. Relative risk compares risk between exposed and unexposed. Odds ratio
is used in case-control studies. Incidence rate is a frequency measure.
Q11. In a screening program, a new test is evaluated against a gold standard. Of 100 people with
disease, 90 test positive. Of 200 without disease, 180 test negative. What is the sensitivity of the
test?
90 percent
80 percent
