This is Part 1 of the Preventive
Medicine Fundamentals 6th Edition
Comprehensive Test Bank by Gordis.
PART 1 of 5
TABLE OF CONTENTS - PART 1 of 5
Chapter 1: Principles of Epidemiology and Disease Occurrence (Questions 1-10)
Chapter 2: Screening and Early Detection (Questions 11-20)
Chapter 3: Immunization and Vaccine-Preventable Disease (Questions 21-30)
Chapter 4: Behavioral Risk Factors and Counseling (Questions 31-40)
Chapter 5: Environmental and Occupational Prevention (Questions 41-50)
CHAPTER 1: PRINCIPLES OF EPIDEMIOLOGY AND DISEASE OCCURRENCE
Q1. A public health team reports 120 new cases of tuberculosis in a city of 400,000 people over one
year. Which measure are they describing?
A. Incidence rate
B. Prevalence
C. Attack rate
D. Case fatality rate
Correct Answer: Incidence rate ✅
Rationale: The correct answer is incidence rate. Incidence measures new cases occurring in a
population over a defined period, which is exactly what the team is reporting. Option B is wrong
because prevalence counts all existing cases, new and old, at a point or over a period. Option C is
wrong because attack rate applies to a defined outbreak population over a short period. Option D is
,wrong because case fatality measures deaths among cases, not new cases. The governing concept is
that incidence reflects risk of developing disease, while prevalence reflects burden of disease at a
given time.
Q2. A survey finds 800 people with diabetes in a town of 20,000. Which measure is being reported?
A. Incidence
B. Prevalence
C. Mortality rate
D. Attack rate
Correct Answer: Prevalence ✅
Rationale: The correct answer is prevalence. Prevalence is the proportion of a population with
a condition at a given time, regardless of when the disease began. Option A is wrong because
incidence counts only new cases over a period. Option C is wrong because mortality measures
deaths. Option D is wrong because attack rate applies to outbreaks. The governing concept is that
prevalence reflects total disease burden, which is influenced by both incidence and duration of
disease.
Q3. A new rapid test for a disease has high sensitivity. Which statement is most accurate?
A. It correctly identifies most people who have the disease
B. It correctly identifies most people who do not have the disease
C. It is unaffected by prevalence
D. It has high positive predictive value in all populations
Correct Answer: It correctly identifies most people who have the disease ✅
Rationale: The correct answer is that high sensitivity identifies most people who have the
disease. Sensitivity is the proportion of true cases correctly identified by the test. Option B is wrong
because that describes specificity. Option C is wrong because predictive values are affected by
prevalence. Option D is wrong because positive predictive value falls as prevalence falls, even with
,high sensitivity. The governing concept is that sensitivity and specificity describe test performance,
while predictive values depend on disease prevalence.
Q4. A screening test has high specificity. Which statement is most accurate?
A. It correctly identifies most people who do not have the disease
B. It correctly identifies most people who have the disease
C. It has high sensitivity
D. It eliminates false negatives
Correct Answer: It correctly identifies most people who do not have the disease ✅
Rationale: The correct answer is that high specificity identifies most people without the
disease. Specificity is the proportion of true non-cases correctly identified as negative. Option B is
wrong because that describes sensitivity. Option C is wrong because specificity and sensitivity are
independent. Option D is wrong because specificity affects false positives, not false negatives. The
governing concept is that specificity matters most when a positive result triggers invasive or costly
follow-up.
Q5. A disease has a long duration and low mortality. Which effect does this have on prevalence?
A. Increases prevalence
B. Decreases prevalence
C. Has no effect on prevalence
D. Eliminates prevalence
Correct Answer: Increases prevalence ✅
Rationale: The correct answer is that long duration increases prevalence. Prevalence depends
on both incidence and duration, so diseases that last longer accumulate more cases at any point in
time. Option B is wrong because longer duration increases rather than decreases prevalence. Option
C is wrong because duration directly affects prevalence. Option D is wrong because prevalence is not
eliminated by duration. The governing concept is that prevalence equals incidence times average
duration, so chronic diseases have high prevalence.
, Q6. An investigator wants to compare disease frequency between two populations with different age
structures. Which adjustment is most appropriate?
A. Age standardization
B. Crude rate comparison
C. Attack rate calculation
D. Case fatality rate
Correct Answer: Age standardization ✅
Rationale: The correct answer is age standardization. Age standardization removes the
confounding effect of different age distributions so that rates can be compared fairly. Option B is
wrong because crude rates reflect the underlying age structure. Option C is wrong because attack
rate applies to outbreaks. Option D is wrong because case fatality measures severity, not frequency.
The governing concept is that adjusted rates allow valid comparison between populations with
different demographic composition.
Q7. A study finds that a disease is more common in older adults. Which type of variable is age in this
context?
A. Confounder
B. Effect modifier
C. Mediator
D. Outcome
Correct Answer: Confounder ✅
Rationale: The correct answer is confounder. Age is associated with both the exposure and the
outcome in many studies, and it can distort the apparent relationship unless controlled. Option B is
wrong because effect modification changes the magnitude of association rather than distorting it.
Option C is wrong because a mediator lies on the causal pathway. Option D is wrong because age is
not the outcome here. The governing concept is that confounders must be identified and controlled
in study design and analysis.
Medicine Fundamentals 6th Edition
Comprehensive Test Bank by Gordis.
PART 1 of 5
TABLE OF CONTENTS - PART 1 of 5
Chapter 1: Principles of Epidemiology and Disease Occurrence (Questions 1-10)
Chapter 2: Screening and Early Detection (Questions 11-20)
Chapter 3: Immunization and Vaccine-Preventable Disease (Questions 21-30)
Chapter 4: Behavioral Risk Factors and Counseling (Questions 31-40)
Chapter 5: Environmental and Occupational Prevention (Questions 41-50)
CHAPTER 1: PRINCIPLES OF EPIDEMIOLOGY AND DISEASE OCCURRENCE
Q1. A public health team reports 120 new cases of tuberculosis in a city of 400,000 people over one
year. Which measure are they describing?
A. Incidence rate
B. Prevalence
C. Attack rate
D. Case fatality rate
Correct Answer: Incidence rate ✅
Rationale: The correct answer is incidence rate. Incidence measures new cases occurring in a
population over a defined period, which is exactly what the team is reporting. Option B is wrong
because prevalence counts all existing cases, new and old, at a point or over a period. Option C is
wrong because attack rate applies to a defined outbreak population over a short period. Option D is
,wrong because case fatality measures deaths among cases, not new cases. The governing concept is
that incidence reflects risk of developing disease, while prevalence reflects burden of disease at a
given time.
Q2. A survey finds 800 people with diabetes in a town of 20,000. Which measure is being reported?
A. Incidence
B. Prevalence
C. Mortality rate
D. Attack rate
Correct Answer: Prevalence ✅
Rationale: The correct answer is prevalence. Prevalence is the proportion of a population with
a condition at a given time, regardless of when the disease began. Option A is wrong because
incidence counts only new cases over a period. Option C is wrong because mortality measures
deaths. Option D is wrong because attack rate applies to outbreaks. The governing concept is that
prevalence reflects total disease burden, which is influenced by both incidence and duration of
disease.
Q3. A new rapid test for a disease has high sensitivity. Which statement is most accurate?
A. It correctly identifies most people who have the disease
B. It correctly identifies most people who do not have the disease
C. It is unaffected by prevalence
D. It has high positive predictive value in all populations
Correct Answer: It correctly identifies most people who have the disease ✅
Rationale: The correct answer is that high sensitivity identifies most people who have the
disease. Sensitivity is the proportion of true cases correctly identified by the test. Option B is wrong
because that describes specificity. Option C is wrong because predictive values are affected by
prevalence. Option D is wrong because positive predictive value falls as prevalence falls, even with
,high sensitivity. The governing concept is that sensitivity and specificity describe test performance,
while predictive values depend on disease prevalence.
Q4. A screening test has high specificity. Which statement is most accurate?
A. It correctly identifies most people who do not have the disease
B. It correctly identifies most people who have the disease
C. It has high sensitivity
D. It eliminates false negatives
Correct Answer: It correctly identifies most people who do not have the disease ✅
Rationale: The correct answer is that high specificity identifies most people without the
disease. Specificity is the proportion of true non-cases correctly identified as negative. Option B is
wrong because that describes sensitivity. Option C is wrong because specificity and sensitivity are
independent. Option D is wrong because specificity affects false positives, not false negatives. The
governing concept is that specificity matters most when a positive result triggers invasive or costly
follow-up.
Q5. A disease has a long duration and low mortality. Which effect does this have on prevalence?
A. Increases prevalence
B. Decreases prevalence
C. Has no effect on prevalence
D. Eliminates prevalence
Correct Answer: Increases prevalence ✅
Rationale: The correct answer is that long duration increases prevalence. Prevalence depends
on both incidence and duration, so diseases that last longer accumulate more cases at any point in
time. Option B is wrong because longer duration increases rather than decreases prevalence. Option
C is wrong because duration directly affects prevalence. Option D is wrong because prevalence is not
eliminated by duration. The governing concept is that prevalence equals incidence times average
duration, so chronic diseases have high prevalence.
, Q6. An investigator wants to compare disease frequency between two populations with different age
structures. Which adjustment is most appropriate?
A. Age standardization
B. Crude rate comparison
C. Attack rate calculation
D. Case fatality rate
Correct Answer: Age standardization ✅
Rationale: The correct answer is age standardization. Age standardization removes the
confounding effect of different age distributions so that rates can be compared fairly. Option B is
wrong because crude rates reflect the underlying age structure. Option C is wrong because attack
rate applies to outbreaks. Option D is wrong because case fatality measures severity, not frequency.
The governing concept is that adjusted rates allow valid comparison between populations with
different demographic composition.
Q7. A study finds that a disease is more common in older adults. Which type of variable is age in this
context?
A. Confounder
B. Effect modifier
C. Mediator
D. Outcome
Correct Answer: Confounder ✅
Rationale: The correct answer is confounder. Age is associated with both the exposure and the
outcome in many studies, and it can distort the apparent relationship unless controlled. Option B is
wrong because effect modification changes the magnitude of association rather than distorting it.
Option C is wrong because a mediator lies on the causal pathway. Option D is wrong because age is
not the outcome here. The governing concept is that confounders must be identified and controlled
in study design and analysis.
