Epidemiological Applications

1. A nurse is using analytic epidemiology when conducting a research project. Which of the following projects is the nurse most likely completing?

a.
Reviewing communicable disease statistics
b.
Determining factors contributing to childhood obesity
c.
Analyzing locations where family violence is increasing
d.
Documenting population characteristics for healthy older citizens

ANS: B

Epidemiology refers not only to infectious epidemics but also to other health-related events. Analytic epidemiology looks at the etiology (origins or causes) of disease.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 151

2. A nurse is employed as a nurse epidemiologist. Which of the following activities would most likely be completed by the nurse?

a.
Eliciting the health history of a client presenting with an illness
b.
Evaluating the number of clients presenting with similar diseases
c.
Performing a physical examination of an ill client
d.
Providing treatment and health education to a client with a disease

ANS: B

Epidemiology differs from clinical medicine, which focuses on the diagnosis and treatment of disease in individuals. Epidemiology monitors the health of the population.

DIF: Cognitive Level: Apply (Application) REF: p. 151

3. Which of the following actions by Florence Nightingale demonstrates her role as an epidemiologist?

a.
She convinced other women to join her in giving nursing care to all the soldiers.
b.
She demonstrated that a safer environment resulted in decreased mortality rate.
c.
She obtained safe water and better food supplies and fought the lice and rats.
d.
She met with each soldier each evening to say goodnight, thereby giving psychological support.

ANS: B

Nightingale examined the relationship between the environment and the recovery of the soldiers. Using simple epidemiological measures, she was able to show that improving environmental conditions and adding nursing care decreased the mortality rates of the soldiers. Nightingale used statistics to document decreased mortality rates when the environmental factors were improved.

DIF: Cognitive Level: Apply (Application) REF: p. 153

4. Which of the following statements describes how nursing in the community is more challenging than nursing in an acute care setting?

a.
There is limited access to information useful to the nurse in giving care in the community.
b.
More paperwork and forms are required when giving care in the home.
c.
It is more challenging to control the environment in the community.
d.
Specialization isn’t possible in the community setting.

ANS: C

In the community, nurses often use epidemiology, since the factors that affect the individual, family, and population group cannot be as easily controlled as in acute care settings. It is essentially impossible to control the environment in the community.

DIF: Cognitive Level: Understand (Comprehension) REF: p. 154

5. Several small communities have applied for grant funding from the state department of health to help decrease their teenage pregnancy rate. Which of the following communities should the nurse suggest receive funding first?

a.
Community A—with 23 single teenage pregnancies in a city of 500
b.
Community B—with 45 single teenage pregnancies in a city of 1000
c.
Community C—with 90 single teenage pregnancies in a city of 2000
d.
Community D—with 90 single teenage pregnancies in a city of 1500

ANS: D

Without doing any actual math, it should be fairly obvious that 23:500, 45:1000, and 90:2000 are all about the same proportion but that 90:1500 is a larger proportion. Doing the math, the pregnancy rates of A, B, and C are 45-46:1000, whereas the rate in Community D is 60:1000.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 156

6. Between 2000 and 2005, 1000 of 10,000 young women ages 17 to 20 years at a university tested positive for a sexually transmitted infection (STI). Of the 1000 diagnosed STIs, 300 were gonorrhea and 500 were chlamydia. Which of the following statements best summarizes these findings?

a.
The proportion of cases of gonorrhea to all STIs was 300:1300.
b.
The proportion of cases of gonorrhea to chlamydia was 300:500.
c.
The proportion of cases of gonorrhea to all STIs was 50%.
d.
The proportion of STIs to the total population was 100:1000.

ANS: D

A proportion is a ratio in which the denominator includes the numerator.

If the proportion is small, we can express the number per 1000. The answer of 300:1300 adds the total of the numerator to the denominator, which is unnecessary because the gonorrhea cases were already included in the denominator. In the answer of 300:500, the ratio comparing gonorrhea to chlamydia does not meet the epidemiological definition of proportion (i.e., the denominator must contain the numerator). Although proportions may be expressed as percentages, in the answer of 50% the percentage reflects the number of gonorrhea cases to all STIs, which doesn’t summarize the total STI problem. The answer of 100:1000 correctly summarizes that 1000 of 10,000 (or 100:1000) young women had the problem.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 156

7. The nursing staff has attempted to screen the entire African-American population in the community for diabetes. Which of the following would provide immediate verification of the success of the nursing staff’s efforts?

a.
An epidemic of diabetes will be recognized.
b.
The incidence of diabetes will increase in the community.
c.
The prevalence of diabetes will decrease in the community.
d.
The risk for diabetes in the community will increase.

ANS: B

If the screening has been successful, more diabetes will be diagnosed and, hopefully, treated. Thus, the incidence of new cases will increase. Overall, prevalence will also increase, but that is not one of the answer options.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 156

8. In a particular community, several high school students were diagnosed with diabetes mellitus Type 2 during the annual high school health fair. Over the next few years, the nursing staff developed and implemented educational programs about the risk factors for diabetes mellitus Type 2 and proper nutrition. Which of the following would be most useful for the nurses to use to determine if they are having any impact?

a.
The epidemic of diabetes in the high school is gradually ending.
b.
The incidence of diabetes is slowly decreasing during screening events.
c.
The prevalence of diabetes is slowly decreasing during screening events.
d.
The risk for diabetes is slowly increasing over time.

ANS: B

Incidence rates and incidence proportions are the measure of choice to study etiology because incidence is affected only by factors related to the risk of developing disease and not to survival or cure. Prevalence is a fairly stable number over time, but incidence reacts more quickly to changes in risk factors or intervention programs. If the educational programs are having the desired impact, the incidence of diabetes being diagnosed will decrease in future screenings.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 157

9. This year 600 of 8000 young women ages 17 to 20 years at a university health center tested positive for a sexually transmitted infection (STI). Which of the following terms best describes this data?

a.
An epidemic
b.
Incidence
c.
Prevalence
d.
Risk

ANS: C

Because we do not have baseline data, we have no way to conclude that this is an epidemic with higher-than-normal results from the screening. Incidence refers to new cases, whereas prevalence means all cases. We don’t know whether the finding represents the first time a woman was told she had an STI or whether she had previously been diagnosed with the problem. Therefore, we can’t say whether these are new cases (incidence), but the results do represent all cases (prevalence). Risk is the probability of developing an STI, but no risk factors are discussed.

DIF: Cognitive Level: Apply (Application) REF: p. 157

10. A nursing staff has successfully screened for diabetes in the community. Which of the following might best persuade the health board to increase funding for diabetic clinics in this community?

a.
An epidemic of diabetes is now recognized and must be addressed.
b.
The incidence of diabetes is now higher than previously recognized in the community.
c.
The prevalence of diabetes is now higher than previously recognized in the community.
d.
The risk for diabetes in the community could decrease if funding is received.

ANS: C

If more people are now being diagnosed with diabetes and need support, more ongoing services will be needed for this population. Incidence may go up and down, but prevalence is a fairly stable number.

DIF: Cognitive Level: Apply (Application) REF: p. 157

11. A public health nurse found that out of the 70 people who ate the potato salad at a school picnic, 63 developed symptoms of food poisoning. Which of the following best describes the attack rate?

a.
63%
b.
70%
c.
90%
d.
100%

ANS: C

The attack rate is the proportion of persons exposed to an agent who develop the disease. Because 63 of the 70 persons became ill, the attack rate is 63:70, or 90%.

DIF: Cognitive Level: Apply (Application) REF: p. 158

12. A man is diagnosed with prostate cancer. Which of the following data should the nurse know to answer the man when he asks, “What are the chances I’ll survive this thing?”

a.
Attack rate
b.
Case fatality rate
c.
Cause-specific morbidity rate
d.
Crude mortality rate

ANS: B

The case fatality rate (CFR) is the proportion of persons diagnosed with a particular disorder (i.e., cases) who die within a specified period. The CFR is considered an estimate of the risk for death within that period for a person newly diagnosed with the disease. Persons diagnosed with a particular disease often want to know the probability of surviving. The CFR provides that information.

DIF: Cognitive Level: Apply (Application) REF: p. 159

13. Which of the following statistics is used by countries to compare the success of their health care systems?

a.
Attack rate
b.
Infant mortality rate
c.
Cause-specific morbidity rate
d.
Cause-specific mortality rate

ANS: B

Infant mortality is used around the world as an indicator of overall health and availability of health care services.

DIF: Cognitive Level: Understand (Comprehension) REF: p. 159

14. A nurse is examining all of the various factors which can lead to disease. Which of the following models would the nurse most likely use?

a.
Epidemiologic triangle
b.
Health promotion
c.
Levels of prevention
d.
Natural history of disease

ANS: A

The epidemiologic triangle categorizes factors as agent, host, or environment. The model encourages the health care provider to examine all the influences that lead to increased risk. Levels of prevention are actions taken to improve health outcomes. Health promotion addresses health improvement, not the risk for disease.

DIF: Cognitive Level: Apply (Application) REF: pp. 159-160

15. A nurse is examining the various factors that lead to disease and suggests several areas where nurses could intervene to reduce future incidence of disease. Which of the following models would the nurse most likely use?

a.
Epidemiologic triangle
b.
Health promotion
c.
Levels of prevention
d.
Web of causality

ANS: D

The web of causality model recognizes the complex interrelationships of many factors interacting to increase or decrease the risk for disease. Causal relationships (one thing or event causing another) are often more complex than the epidemiologic triangle conveys. With all the various antecedents identified, the nurse can then decide in which areas interventions are possible.

DIF: Cognitive Level: Apply (Application) REF: p. 160

16. Which of the following actions would a nurse take to reduce the high incidence of coronary artery disease (CAD) in a community?

a.
Introduction of a heart-healthy curriculum beginning in the first grade, presentations on diet and exercise for the community at large, and special education sessions for high-risk populations
b.
Provision of online activities related to prevention of cardiac disease, smoking reduction programs, and blood pressure screenings
c.
Distribution of handouts, including age-appropriate games, self-assessments, and education on heart-healthy lifestyles; availability of community screenings for hyperlipidemia in persons age 35 and older; and walking programs for those affected with CAD
d.
Enrollment of clients with CAD into cardiac rehabilitation programs, routine evaluation of effectiveness of CAD treatment regimens, and participation in clinical trials that evaluate interventions for those diagnosed with CAD

ANS: C

Education in schools, the community, and high-risk populations focuses only on primary prevention activities. Online activities focus only on primary and secondary prevention. Efforts focused only on those who already have CAD are not primary prevention. Distributing handouts 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 increase the likelihood of positive outcomes for the community as a whole.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 160

17. A school nurse wants to decrease the incidence of obesity in elementary school children. Which of the following describes a secondary prevention intervention that the nurse could implement?

a.
Giving a presentation on the importance of exercise and physical fitness
b.
Designing a game in which students select healthy food choices
c.
Weighing students to identify those who are overweight
d.
Putting students on a diet if they weigh greater than 20% of their ideal weight

ANS: C

Secondary prevention refers to interventions that increase the probability that a person with a condition will have the condition diagnosed early. Health screenings are the mainstay of secondary prevention. Weighing students and assessing whether the weight is higher than recommended will allow for early intervention so that obesity may be avoided.

DIF: Cognitive Level: Apply (Application) REF: pp. 160-161

18. A nurse advises a client with osteoporosis to have three servings of milk or dairy products daily. Which of the following levels of prevention is being used by the nurse?

a.
Primary prevention
b.
Secondary prevention
c.
Tertiary prevention
d.
Treatment, but not prevention

ANS: C

Interventions that prevent 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 nurse aims to ensure that enough calcium is available to limit worsening of the osteoporosis.

DIF: Cognitive Level: Apply (Application) REF: p. 161

19. A nurse has only a regular blood pressure cuff when conducting a health screening for all of the residents of a community. Which of the following may be lacking when obtaining blood pressure readings?

a.
Reliability
b.
Sensitivity
c.
Specificity
d.
Validity

ANS: D

Validity is the accuracy of a test or measurement, or how closely it measures what it claims to measure. With only one regular BP cuff, the nurse cannot obtain accurate measurements on those who are extremely obese or extremely thin. A thigh cuff and a pediatric cuff would allow the nurse to obtain accurate—that is, valid—measurements.

DIF: Cognitive Level: Apply (Application) REF: p. 162

20. A nurse is administering a tuberculosis skin test to a client who has AIDS. Which of the following results should the nurse anticipate when using this screening test?

a.
Decreased positive predictive value
b.
Decreased reliability
c.
Decreased sensitivity
d.
Decreased specificity

ANS: C

Persons with immune deficiencies may have a negative tuberculosis skin test even though they are infected. Sensitivity is the extent to which a test identifies those individuals who have the condition being examined. AIDS is an acquired immune deficiency; thus, clients with AIDS may have a false-negative response to TB skin tests; that is, they have the disease but the test is not sensitive enough to detect infection in these individuals. Therefore, there is decreased sensitivity with those clients.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 162

21. Persons in an auditorium may have been exposed to a disease. If they are infected, it is crucial that they receive immediate treatment and not take the disease home to their families. Which of the following characteristics would be most important to consider when selecting the screening test to be used?

a.
The negative predictive value
b.
The positive predictive value
c.
The sensitivity of the test
d.
The specificity of the test

ANS: C

Because it is most important to identify every case, the sensitivity of the test is crucial. High sensitivity is needed when early treatment is important and when identification of every case is important.

DIF: Cognitive Level: Apply (Application) REF: p. 162

22. A woman is sitting in a corner of the clinical waiting room, crying audibly. The nurse asks, “What’s wrong? Can I help?” The woman responds, “They just told me I have a positive mammogram and I need to see my doctor for follow-up tests. I know I’m going to die of cancer. How can I tell my family?” Which of the following information does the nurse need to know in order to help the woman cope with this finding?

a.
The negative predictive value of mammography
b.
The positive predictive value of mammography
c.
The reliability of mammography
d.
The validity of mammography

ANS: B

The positive predictive value 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.

DIF: Cognitive Level: Apply (Application) REF: p. 163

23. The administration at a local medical center examines the trends in health problems when developing long-range plans for staffing and space allocation. Which of the following sources of information would be most helpful?

a.
Local data drawn from a professional survey in the city
b.
The National Health Interview Survey
c.
The National Hospital Discharge Survey
d.
The state’s vital statistics

ANS: A

The National Health Interview Survey and the National Hospital Discharge Survey both provide information on the health status and behaviors of the national population. For many studies, however, the only way to obtain the needed information is to collect the required data in a study specifically designed to investigate a particular question.

DIF: Cognitive Level: Apply (Application) REF: p. 163

24. Statistics clearly demonstrate that there are significantly more cases of a disease in one particular neighborhood than in all the rest of the city. Assuming all else is the same, which of the following is the most likely explanation for a single neighborhood having such a different pattern of illness?

a.
A cultural or ethnic concentration in the neighborhood
b.
The geographical location of the neighborhood within the city
c.
A statistical fluke without meaning
d.
The time of year the different statistics were collected throughout the city

ANS: A

Although any explanation is possible, the most probable reason is that there is a cultural or ethnic concentration in that particular neighborhood that has a different lifestyle pattern, resulting in different health outcomes.

DIF: Cognitive Level: Apply (Application) REF: p. 165

25. Two women seem to agree on almost everything from favorite music to favorite media stars to the best way to prepare a meal. Which of the following best explains this similarity in the two women?

a.
They are both members of the same birth cohort.
b.
They are close friends.
c.
They attended the same school.
d.
They both go the same church.

ANS: A

Being close friends is probably the result of the similarity rather than the cause. However, being born at about the same time would mean both women have lived through similar social events and media occurrences and therefore would have much in common. Going to the same school or the same church, depending on the size of the institutions, might not result in any personal interaction whatsoever.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 167

26. A nurse reports that in comparison to all the children in a particular school, the children who are members of the Cub Scouts have 0.3 risk for obesity before entering the sixth grade. Which of the following recommendations would the nurse make to the new parents of two boys who had just moved into this school’s neighborhood?

a.
Discourage the parents from enrolling their sons in Cub Scouts because of the risk.
b.
Don’t say anything about Cub Scouts, because it isn’t relevant to nursing care.
c.
Encourage the parents to enroll their sons in Cub Scouts.
d.
Share the finding and let the parents draw whatever conclusions they feel appropriate.

ANS: C

Relative risk is an estimation of the risk of acquiring a problem for those who are exposed compared with those who are unexposed. As the risk for obesity is less for those that are members of Cub Scouts, joining the group is protective and reduces the incidence among members.

DIF: Cognitive Level: Analyze (Analysis) REF: pp. 167-168

27. A principal comments to the school nurse that it seems there are a lot more problems with asthma among the students than there were before the school was remodeled a couple of years ago. The nurse investigates the principal’s observation by reviewing all the school records to determine visits to the health office because of asthma by week and month for the past 5 years. Which of the following best describes the type of study the nurse is conducting?

a.
Descriptive epidemiological study
b.
Ecological study
c.
Prospective cohort study
d.
Retrospective cohort study

ANS: D

Retrospective cohort studies rely on existing records to define a cohort that is classified as having been exposed or unexposed at some time in the past. In this case, the issue is whether there is some health risk in the new building addition that is increasing frequency of visits to the school nurse because of asthma.

DIF: Cognitive Level: Apply (Application) REF: p. 168

28. Which of the following types of study should the nurse researcher choose if the goal is to identify the long-term benefits and risks of a particular nursing intervention for senior citizens living in the community?

a.
Cross-sectional study
b.
Ecologic study
c.
Clinical trial
d.
Retrospective analysis

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.

DIF: Cognitive Level: Apply (Application) REF: p. 170

29. A teacher recommends that surveys to obtain data on drug use be given to high school students when they meet for various school organizations. Which of the following best describes why the nurse would reject this suggestion?

a.
This method of data collection would result in classification bias.
b.
This method of data collection would result in confounding bias.
c.
This method of data collection would result in personal bias.
d.
This method of data collection would result in selection bias.

ANS: D

Any study is subject to bias resulting from selective choice. There may be a difference between students who choose to belong to an organization and students who choose not to join an organization. Selection bias occurs when selection procedures are not representative of the population as a whole. In this instance, the goal is to determine drug use of all students at the school. If only students who join school organizations are selected, those who do not join organizations will not be represented.

DIF: Cognitive Level: Apply (Application) REF: p. 170

30. A nurse is investigating a bacterial illness that has caused a health problem in the community. Only some of the people exposed to the bacteria have become ill. Which of the following factors best explains why this would have happened?

a.
Chemical agent factors
b.
Environmental factors
c.
Host factors
d.
Physical agent factors

ANS: C

The epidemiologic triangle includes the agent, host, and environment. The bacteria were the agent so chemical and physical agents are not relevant. The environment was apparently the same for everyone, since all were exposed to the bacteria. Therefore, only differences in host factors can explain why some became ill and some were able to fight off the bacterial infestation.

DIF: Cognitive Level: Apply (Application) REF: p. 160

MULTIPLE RESPONSE

1. Which of the following explains why contagious infections are becoming a central focus of public health? (Select all that apply.)

a.
Americans are fearful of terrorists using biological agents.
b.
Awareness of human susceptibility to animal diseases has been publicized.
c.
Drug-resistant strains of “old” diseases have evolved.
d.
Media coverage exaggerates the dangers of exposure to crowds.

ANS: A, C

New infectious diseases and new forms of old diseases, such as drug-resistant strains of TB, have emphasized the dangers of infectious diseases. Potential threats from terrorist use of infectious agents have also emphasized infectious diseases.

DIF: Cognitive Level: Understand (Comprehension) REF: p. 154

2. A nurse is concerned about the high incidence of STDs in the community college population and sets up a special STD screening. Which of the following groups of students would be encouraged to attend? (Select all that apply.)

a.
Sexually active students currently receiving treatment for an STD
b.
Sexually active students who had been screened the previous year
c.
Students who claimed to not be sexually active and do not plan to become sexually active
d.
Students who are sexually active but never “go all the way”

ANS: B, C, D

Those already diagnosed with the problem are not at risk, because they already have the condition and are no longer at risk for developing it.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 156

3. A nurse is planning to host a health screening at a large urban mall. Which of the following variables will help the nurse determine which screenings should be included? (Select all that apply.)

a.
Adequate space for persons to lie down after testing until side effects are reduced
b.
Health problems for which the specific population is at risk
c.
Whether adequate privacy can be obtained for the invasive or embarrassing procedures
d.
Whether health care providers are available to follow up on any positive screening results

ANS: B, D

The screening tests should be reliable, valid, fast, and inexpensive. They should have few side effects, be minimally invasive, and be capable of detecting enough new cases to warrant the effort and expense. Results should be known immediately. No tests should be used that have negative side effects, are invasive, or cause embarrassment. Ethically, nurses should not screen for any problem unless they can refer those with positive results to a source for follow-up testing and treatment.

DIF: Cognitive Level: Analyze (Analysis) REF: pp. 161-162

4. A nurse believes a new mouth care procedure (MCP) is causing more mouth problems than it is helping to avoid. Which of the following must be present for the nurse to go to administration with confidence that the new mouth care procedure (MCP) is causing problems? (Select all that apply.)

a.
A plausible explanation of how the new MCP could cause harm
b.
A strong feeling that the MCP is the cause
c.
Consistently seeing mouth inflammation in many of the patients who have received the MCP
d.
Documentation from patient records that mouth inflammation in clients did not occur until after the new procedure was implemented

ANS: A, C, D

Strength of association is suggested by the fact that patients who did not receive the MCP and patients seen on the floor before the new MCP did not have problems, whereas patients who received the new MCP are having problems. Seeing the problems in many of the patients suggests a consistency. The fact that those who had the procedure more often have worse problems suggests a dose-response relationship. A plausible explanation of how the new procedure could cause harm enhances the biological risk. Feelings alone are not convincing. A study should be set up to confirm or dispute the nurse’s hypothesis. Although one would hope that previous testing would have been done before the product was released to market, the product could be safe for healthy persons but a risky process for those with compromised immunity or those who are under stress.

DIF: Cognitive Level: Analyze (Analysis) REF: p. 171