Chapter 8: Epidemiological Applications

Question 1

1. Epidemiology would be a primary tool used by the nurse scientist for researching which
   topic?
   a. Experiences of cancer care services
   b. Contributing factors to childhood obesity
   c. Morbidity statistics
   d. Social characteristics and traits of healthy older adults

Answer 1

ANS: B
As the basic science of public health, epidemiology refers not only to epidemics of infections
but also to other health-related events in a population. Analytical epidemiology looks at the
etiology (origins or causes) of a disease—such as childhood obesity.

Question 2

2. In which of the following activities does the community health nurse (CHN) act in the role of
   a nurse epidemiologist?
   a. Eliciting the health history of a client presenting with an illness
   b. Performing a physical assessment of an ill client
   c. Providing treatment and health education to a client with a disease
   d. Evaluating the number of clients presenting with similar diseases

Answer 2

ANS: D
Epidemiology differs from clinical medicine, which focuses on the diagnosis and treatment of
disease in individuals. Epidemiology investigates the distribution, or the patterns, of health
events in populations and the determinants or the factors that influence those patterns

Question 3

3. During the years 2011 to 2016, in a particular district, 1,000 of 10,000 girls aged 16 to 18
   years tested positive for a sexually transmitted infection (STI). Of the 1,000 diagnosed STIs,
   300 were gonorrhea and 500 were chlamydia. Which statement would the CHN recognize as
   being true?
   a. The proportion of cases of gonorrhea to all STIs was 300:1,300.
   b. The proportion of cases of gonorrhea to chlamydia was 300:500.
   c. The proportion of STIs to the total population was 10 per 1,000.
   d. The proportion of cases of gonorrhea to all STIs was 50%.

Answer 3

ANS: C
In epidemiology, a proportion is a ratio in which the denominator includes the numerator. In
public health statistics, if the proportion is small, we can express the number per 1,000.

Question 4

4. Which model best explains the reasons why homeless individuals are at increased risk of
   disease as a result of multiple agent, host, and environmental factors?
   a. The web of causality
   b. The epidemiological triangle
   c. The levels of prevention
   d. The Health Promotion Model

Answer 4

ANS: A
The web of causality refers to the interrelationship of multiple factors that interact to influence
health. The epidemiological triangle, by contrast, categorizes factors as agent, host, or
environment but does not address the interactions of these factors. Levels of prevention are
actions taken to improve health outcomes, whereas health promotion addresses health
improvement, not risk of disease.

Question 5

5. Which actions could be taken by the CHN who wishes to provide secondary prevention to
   decrease the incidence of obesity in elementary school children?
   a. Giving a presentation on the importance of exercise and physical fitness
   b. Designing a game in which students need to make healthy food choices
   c. Weighing students to identify those who are overweight
   d. Putting students on a diet if they weigh more than 20% of their ideal weight

Answer 5

ANS: C
Secondary prevention refers to interventions that increase the probability of early diagnosis of
a condition. Health screenings are the mainstay of secondary prevention. Weighing students
and identifying higher-than-recommended weight will enable early intervention to prevent
obesity.

Question 6

6. What is a CHN implementing when advising a client with osteoporosis to have three servings
   of milk or dairy products daily?
   a. Primary prevention
   b. Secondary prevention
   c. Tertiary prevention
   d. Treatment, but not prevention

Answer 6

ANS: C
Interventions that prevent the worsening of a condition are tertiary prevention activities. In
this instance, the client already has a health problem (osteoporosis). By advising adequate
dairy intake, the CHN aims to ensure that the client gets enough calcium to prevent worsening
of the osteoporosis.

Question 7

7. What would be the best choice for the nurse researcher who wishes to identify the long-term
   benefits and risks of a treatment for hyperlipidemia?
   a. A cross-sectional study
   b. An ecological study
   c. A clinical trial
   d. A retrospective analysis

Answer 7

ANS: C
The goal of a clinical trial is to evaluate the effectiveness of an intervention. Clinical trials are
generally the best way to show causality.

Question 8

8. Which action proposed to prevent problems related to coronary artery disease (CAD) in a
   region with a high prevalence is most likely to have positive outcomes?
   a. Introducing heart health information in the curriculum as early as grade 1,
   presentations on diet and exercise for the community at large, and special
   education sessions for high-risk populations
   b. Providing online activities related to the prevention of cardiac disease, smoking
   cessation programs, and blood pressure screenings
   c. Distributing handouts about age-appropriate games, self-assessments, and
   educational materials on heart-healthy lifestyles, availability of community
   screenings for hyperlipidemia in persons age 35 years and older, and walking
   programs for those affected by CAD
   d. Enrolling clients with CAD into cardiac rehabilitation programs, routinely
   evaluating the effectiveness of CAD treatment regimens, and participating in
   clinical trials that evaluate interventions for those diagnosed with CAD

Answer 8

ANS: C
Early introduction of health information focuses only on primary prevention activities.
Provision of online activities focuses only on primary and secondary prevention. Enrollment
of clients with CAD into cardiac rehabilitation programs focuses only on those already
affected by CAD. The correct answer includes all three levels of prevention to target all
members of the population. Targeting all members of the population and implementing all
levels of prevention increases the likelihood of positive outcomes for the community as a
whole.

Question 9

9. People with immune deficiencies may have a negative tuberculosis (TB) skin test (Mantoux),
   even though they are infected. Which of the following measurements will the CHN conclude
   to be low when the TB skin test is given to persons with acquired immune deficiency
   syndrome (AIDS)?
   a. Positive predictive value
   b. Reliability
   c. Sensitivity
   d. Specificity

Answer 9

ANS: C
Sensitivity is the extent to which a test identifies those individuals who have the condition.
AIDS being an acquired immune deficiency, clients with the disease may have a falsenegative response to TB skin tests; that is, they may have the disease but the test is not
sensitive enough to detect infection in these individuals

Question 10

10. The CHN can enhance the sensitivity and specificity of a test by using its predictive value.
    Which one of the following best defines positive predictive value?
    a. The proportion of persons with a negative test who are actually disease-free
    b. The variation inherent in the trait being measured
    c. Any inconsistency in the testing instrument
    d. The proportion of persons with a positive test who actually have the disease

Answer 10

ANS: D
Positive predictive value (also called predictive value positive) is the proportion of persons
with a positive test who actually have the disease, interpreted as the probability that an
individual with a positive test has the disease.

Question 11

11. A CHN determines that out of 8,000 women screened for breast cancer, 35 have previously
    been diagnosed with a cancer event and 20 are newly diagnosed with a cancer event. What is
    the prevalence rate in this group?
    a. 55
    b. 0.7
    c. 70%
    d. 55/8,000

Answer 11

ANS: D
The prevalence rate identifies the number of persons in a population that have a disease or
have experienced an event at a specific period (old and new cases included). The formula for
calculating prevalence rate is number of population with the disease divided by the number of
individuals at risk.

Question 12

12. The CHN knows that a regular-sized blood pressure (BP) cuff will provide readings that are
    falsely high if used to measure BP in an obese person and will provide readings that are
    falsely low if used to measure BP in a small or very thin person. Which of the following does
    a regular-sized BP cuff lack when used to measure BP in all individuals?
    a. Reliability
    b. Sensitivity
    c. Specificity
    d. Validity

Answer 12

ANS: D
Validity is the accuracy of a test or measurement or how closely it measures what it claims to
measure.