Upgrade to remove ads
Only $35.99/year

Chapter 05: Epidemiology

Terms in this set (34)

An epidemiologist has written a summary of a food poisoning outbreak, including its cause and ways to prevent it from occurring in the future. Which of the following best describes what has been done?

a. Analytic epidemiology
b. Descriptive epidemiology
c. Prospective cohort study
d. Retrospective cross-sectional survey
ANS: B

There are two principal types of epidemiology: (1) analytic epidemiology and (2) descriptive
epidemiology. Descriptive epidemiology describes the amount and distribution of disease, which may suggest possible causes. These causes can then be confirmed or corrected through more advanced methods of research.
Two brothers played with their cousin. One brother later became quite ill, whereas the other did not. Which of the following provides the best explanation for this occurrence?

a. Difference in length of time exposed
b. Difference in how actively the children played
c. Difference in genetic inheritance between the two brothers
d. Difference in lifestyle between the two brothers
ANS: C

Assuming the two brothers lived in the same household, the environment and the agent or infectious organisms are the same. The only difference could be between the two brothers themselves and their
genetic inheritance.
In which of the following circumstances would it be more helpful to use the wheel model of
epidemiology than the epidemiological triangle model?

a. When factors outside the triangle model are involved
b. When there are multiple causes for a chronic disease
c. When research has not yet determined the exact cause
d. When trying to explain the situation to a lay person
ANS: B

The epidemiological triangle model of agent-host-environment is very useful, especially with single-cause infectious diseases. However, with the multiple factors involved in chronic diseases, the wheel model is
more useful in analyzing and identifying the multiple variables.
Which of the following best describes the importance of discovering all of the variables that may be involved in creating a disease state in some persons?

a. People want an explanation of why they are ill.
b. Knowing causes helps obtain funds for research to try to create a cure.
c. Finding variables that are susceptible to prevention or early intervention is important.
d. It is important to educate communities on how to avoid any risk factors.
ANS: C

Identifying risk factors is critical to creating or discovering specific prevention and intervention approaches that reduce chronic disease morbidity and mortality. Because some risk factors cannot be avoided, knowing other risk factors involved allows for more possibilities of preventing the problem. These variables need to be identified first so that health care providers are able to provide an explanation to persons as to why they are ill, obtain funding for research for the problem, and educate the community about the avoidance of the known risk factors.
Which of the following best describes the advantage of the web of causation model in comparison with the epidemiological triangle model?

a. The web of causation model is easier to understand and use.
b. The web of causation model is more widely known and publicized.
c. The web of causation model is more recent and current.
d. The web of causation model shows the relationships among variables.
ANS: D

Although it is a more recently created model, the web of causation model is more useful because it illustrates the complexity of relationships among causable variables. It is not easier to understand and use
as it has more variables than the three (agent, host, and environment) in the epidemiological model.
Which of the following has been determined to be a major variable in transmission of sexually transmitted infections?

a. The pathogenesis of the involved agents
b. The susceptibility of the host
c. The environment in which the hosts live
d. The amount of sex education provided in the schools
ANS: C

The researchers concluded that ecosocial or contextual conditions strongly enhance sexually transmitted infection risk by increasing sexual risk behaviors and the likelihood of exposure to infection. Thus, the
environment has been determined to be a more important variable in sexually transmitted infections than
the pathogenesis, susceptibility, and the amount of sex education provided.
A community health nurse determined exactly how many cases of a particular disease were
currently occurring in the community. Which of the following actions should the nurse take before determining what interventions should be planned?

a. Analyze whether the disease was a priority to the nurse's agency
b. Compare the current rate with the previous rate of disease
c. Determine what resources are available to intervene
d. Share the findings with the public health agency leadership
ANS: B

No conclusions can really be drawn from just knowing a number. Only by converting that count to a rate and then comparing the rate with the previous rate, or with the rate in the broader environment or a
similar community nearby, can any conclusions be drawn as to whether there is a problem or intervention needed. Once the rate has been calculated, the nurse will be able to share the findings with leadership,
determine the resources available to intervene if necessary, and determine if the disease is a priority.
People were very concerned about another outbreak of swine flu. All care providers were asked to report, without individual names, any new cases to the public health department for tracking. Which of the following would be most helpful for the local media to report to keep citizens informed?

a. The ongoing incidence rate
b. The ongoing prevalence of the illness
c. How many were hospitalized
d. How many had died so far in local hospitals and care facilities
ANS: A

As only new cases were being reported to the health department, the media could only report the ongoing
incidence rate, that is, the number of new cases reported each day.
When trying to determine whether the swine flu outbreak was getting worse, which of the
following rates should be carefully observed?

a. The crude death rate
b. The age-specific death rate
c. The swine flu incidence rate
d. The swine flu prevalence rate
ANS: C

The incidence rate of new cases would be most useful for detecting short-term acute disease changes, because the swine flu duration is usually relatively short.
A newspaper published an article stating that the athletic banquet at the local high school had approximately 1000 family members in attendance. Exactly 650 persons became ill within 24 hours, complaining of severe diarrhea, vomiting, and cramping. Which of the following best describes the attack rate?

a. 650 persons
b. 1000 persons
c. 650:1000
d. 6.5%
ANS: C

Rates are calculated by the number of people with the problem over the number exposed to the problem.
In this case, 650 persons out of the 1000 at the banquet complained of illness. Although this rate could be presented as an attack rate of 65%, 6.5% is incorrect.
In a particular community, the rate of new cases of diabetes and the rate of new cases of flu during the month of January were precisely the same. Which disease would have the higher prevalence rate?

a. As an acute condition, flu would have the higher prevalence rate.
b. As a chronic condition, diabetes would have the higher prevalence rate.
c. Flu would have the higher prevalence rate because people can get flu several times in one season.
d. Flu would have the higher prevalence rate because it is so contagious.
ANS: B

Diabetes would have the higher prevalence rate because it is a long-term chronic condition that typically does not decrease. Although flu might have a higher incidence rate of new cases, because flu is typically of short duration, the prevalence rate would remain low. Flu is contagious, which could increase the incidence rate but not the prevalence rate.
Which of the following statements best describes why the incidence and prevalence of gonorrhea is unknown?

a. Gonorrhea is not a reportable condition.
b. Gonorrhea can vary in how long the infection remains in the body.
c. Gonorrhea can be cured with antibiotics, so people do not remain infected.
d. People are ashamed to admit they have gonorrhea.
ANS: A

Morbidity rates (incidence and prevalence rates) are not available for many conditions because surveillance of many chronic diseases is not widely conducted. Furthermore, morbidity rates may be subject to underreporting when they are available. In other words, there is no responsibility to report cases
of most diseases, including gonorrhea. Information is only available related to conditions where care providers are required to report that specific condition or where those affected die and mortality data are available.
Which of the following groups should be used to determine the community's pregnancy rate?

a. All persons between 15 and 45 years old in the community
b. The total population of the community
c. The total population of women in the community
d. Women between 15 and 45 years old in the community
ANS: D

Although pregnancy is not specifically addressed, the text stresses that only those susceptible to a particular condition should be considered in the denominator. In the case of pregnancy, only women of childbearing age are susceptible.
Which of the following research studies would determine the attributable risk of a sedentary
lifestyle in cardiac disease?

a. Measuring all cases of cardiac problems in a specific community
b. Comparing the number of persons with cardiac disease among athletes with the
number among nonathletes in a community
c. Subtracting the rate of cardiac disease among athletes from the rate of cardiac
disease among nonathletes
d. Calculating the relative risk and then subtracting the attack rate to determine the
attributable risk
ANS: C

Attributable risk is determined by subtracting the rate of disease among nonexposed individuals (such as athletes) from the rate of disease among those exposed (the individuals with a sedentary lifestyle).
A nurse conducted a study of two skin lotions: (1) an inexpensive one and (2) an expensive one. The nurse found that there was a relative risk of 0.7 for skin sores using the inexpensive one and a relative risk of 1.2 using the expensive one. Which skin lotion should the nurse use?

a. Impossible to tell from the data given
b. It made no difference which lotion was used
c. The expensive lotion
d. The inexpensive lotion
ANS: D

A risk factor of less than one means the factor is actually protective, so the inexpensive lotion is helpful in preventing skin sores. A risk factor of more than one means the factor increases risk, so using an expensive lotion increases the probability of getting a skin lesion.
Which of the following best describes a model that demonstrates the progression of disease from prepathogenesis through disease outcome?

a. Epidemiological model
b. Ecosocial model
c. Natural history model
d. Wheel model
ANS: C

The natural history of disease model explains disease from prepathogenesis through resolution of the disease process. The epidemiological model involves the epidemiological triangle: agent, host, and
environment. The ecosocial model emphasizes the role of evoloving macro-level socio-environmental factors to understand health and illness. The wheel model subscribes to multiple-causation rather than
single-causation disease theory, and is more useful in analyzing complex chronic conditions and
identifying factors that are amendable to intervention.
A student athlete receives a screening examination before being active in school sports. Which of the following levels of prevention is being used?

a. Health prevention
b. Primary prevention
c. Secondary prevention
d. Tertiary prevention
ANS: C

Screening, because it may result in early diagnosis and treatment, is secondary prevention. Primary
prevention refers to interventions that occur before the disease develops. Tertiary prevention focuses on limitation of disability and the rehabilitation of those with irreversible disease. Health prevention is not considered to be a level of prevention.
For which of the following would a screening test be most appropriate?
a. Disease A, which must be caught early because society punishes those known to
have the disease
b. Disease B, which can be controlled if caught early in the disease process
c. Disease C, which people need to know whether they have contracted, even though
there is no treatment for the disease
d. Disease D, because people may want to use that information in family planning
ANS: B
It is extremely useful to the individuals concerned and society if screening can lead to early diagnosis and
successful control of the disease process. There is no point in doing a screening if there is no treatment or
if there is a known risk of social stigma and discrimination if it becomes known that the person has the
disease. Discussion and disagreement continue as to whether genetic information should be used in family
planning.
One hundred women received notification that their screening tests suggested that they might have a serious health problem. Which of the following actions should the nurse take to ensure that they will complete follow-up testing?

a. Compliment them on their willingness to be tested and suggest an immediate
appointment before they have too much time to think about the issue.
b. Imply that the test could be wrong; the testing materials may not be effective, but
the only way to be sure is to be tested further.
c. Point out that screening is only suggestive and that not all positive screenings mean they actually have the health problem.
d. Reassurance is not therapeutic; reality must be faced. Emphasize the need for immediate treatment.
ANS: C

Not all positive screening results are confirmed with further diagnostic testing. The positive predictive value of a test (proportion of true positive results relative to all positive test results) is usually known for
any screening test. Although one could argue that the test could be wrong, it is more therapeutic—because you want people to attend future screenings—to emphasize that screening is only suggestive than to say the screening test is inaccurate.
Which of the following would be the best method to increase the positive predictive value of a screening test?

a. Test a large population at once
b. Test a group at high risk for the health problem
c. Use a very sensitive screening test
d. Use a very specific screening test
ANS: B

The positive predictive value is affected by what proportion of the tested population has the problem. To increase the positive predictive value, screen populations most at risk for the problem. Testing a large
population at once, using a very sensitive or very specific screening test would not increase the positive predictive value of a screening test.
Which of the following is the most effective way to determine if Healthy People 2020 is improving the health of Americans?

a. Availability of relatable data on total population's health problems
b. Comprehensive and systematically collected surveillance data on the health status of various population groups
c. Increased financing to allow ongoing collation of information
d. Willingness of individuals to share health information with the federal government
ANS: B

Effectiveness of Healthy People 2020 depends on the availability of reliable baseline and continuing data to characterize health problems and evaluate goal achievement. Surveillance is crucial. Without
surveillance data, there is no relatable data available. Increased financing will not assist in determining if the health of Americans is improving. Although it is important for individuals to be willing to share health
information so that data collection can be completed, individual health information alone will not be an
effective determinant of the health of Americans.
A researcher is examining potential risk factors in comparison with disease at a specific time
through collecting data regarding current exercise, sleep patterns, and current health status among 12-year-olds. Which of the following research studies would be most appropriate?

a. Cross-sectional study
b. Prospective study
c. Retrospective study
d. True experiment
ANS: A

By definition, a cross-sectional study examines relationships between potential causal factors and disease at a specific time. A prospective study monitors a group of disease-free individuals to determine if and when disease occurs. A retrospective study compares individuals with a particular condition or disease
with those who do not have the disease. A true experiment involves both an experimental group who receives an intervention and a control group who does not receive an intervention.
A researcher, interested in the onset of early menses, compared the life experiences and history of 1000 14-year-old girls, half of whom had monthly periods and half of whom did not, to determine what variables might be observed. Which of the following would be the most appropriate categorization of this study?

a. Cross-sectional study
b. Prospective study
c. Retrospective study
d. True experiment
ANS: C

When a study looks at individuals with a particular condition in comparison with those who do not have the disease, based on their exposures to various life situations, it is a retrospective study; that is, the study
requires participants to look back at previous experiences. A cross-sectional study examines relationships between potential causal factors and disease at a specific time. A prospective study monitors a group of disease-free individuals to determine if and when disease occurs. A true experiment involves both an experimental group who receives an intervention and a control group who does not receive an
intervention.
One famous study followed a cohort of nurses over their lives, collecting data and health histories as they aged. Which of the following would be the most appropriate categorization of this study?

a. Cross-sectional study
b. Prospective study
c. Retrospective study
d. True experiment
ANS: B

Prospective studies monitor a group of individuals to determine if and when disease occurs. A cross-sectional study examines relationships between potential causal factors and disease at a specific time. A
retrospective study compares individuals with a particular condition or disease with those who do not have the disease. A true experiment involves both an experimental group who receives an intervention and a control group who does not receive an intervention.
A researcher wanted to engage in the best possible research design to obtain reliable information about the possible cause(s) of a disease. Which of the following designs would the researcher choose?

a. Cross-sectional study
b. Descriptive study
c. Prospective study
d. Retrospective study
ANS: C

The most advantageous research design, because it obtains more reliable information and can more easily establish a stronger temporal relationship between presumed causal factors and their effects, is a longitudinal cohort prospective study. A cross-sectional study examines relationships between potential causal factors and disease at a specific time. A descriptive study focuses on the amount and distribution of health and health problems within a population. A prospective study monitors a group of disease-free
individuals to determine if and when disease occurs. A retrospective study compares individuals with a particular condition or disease with those who do not have the disease.
A researcher has limited time and funds. Which of the following research designs would be most appropriate?

a. Cohort study
b. Incidence study
c. Longitudinal study
d. Retrospective study
ANS: D

Because longitudinal, cohort, or incidence studies are costly in terms of resources and staff and often lose subjects over time, a retrospective study may be used because it is faster and less demanding of resources.
On the basis of findings related to elevated blood levels of cholesterol, a researcher wanted to determine whether a new drug would notably lower the blood levels of cholesterol in otherwise healthy persons. Which of the following studies would the researcher most likely use?

a. Cross-sectional study
b. Experimental study
c. Prospective study
d. Retrospective study
ANS: B

Experimental design is used to test treatment and prevention strategies. Subjects are randomly assigned to the experimental group to obtain the new drug while the control group receives a placebo or alternative.
The changes in blood cholesterol level would then be measured. A cross-sectional study examines
relationships between potential causal factors and disease at a specific time. A prospective study monitors a group of disease-free individuals to determine if and when disease occurs. A retrospective study compares individuals with a particular condition or disease with those who do not have the disease.
A client has developed pellagra because of a lack of certain B vitamins. Which of the following best describes the classification of the nutritional deficiency?

a. Relative risk factor
b. Agent factor
c. Environment factor
d. Host factor
ANS: B

Nutritional deficiencies are included under agent factors. Although too much of an agent can cause disease (such as obesity related to diabetes), so can too little of an agent. Relative risk indicates the extent
of excess risk incurred by exposure relative to nonexposure. Host factors are intrinsic factors and describe
one's susceptibility or response influence to the exposure to the agent, such as genetics, age, sex,
ethnicity, and human behavior. Environment factors are extrinsic factors and they influence the existence of the agent, exposure, or susceptibility to the agent such as physical environment, biological environment, and socioeconomic environment.
Which of the following best describes the Tuskegee Syphilis Study?

a. It provided excellence in research design.
b. It used an extensive subject base leading to confirmed conclusions.
c. It developed information about the causes and treatment of syphilis.
d. It implemented unethical and racist treatment of uninformed subjects.
ANS: D

As treatment was knowingly withheld over many years resulting in incredible harm to the subjects and their families, public outrage over unethical, racist, and discriminatory behavior of the researchers continues today.
An epidemiologist is gathering data to determine which factors may lead to disease. Which of the following data will be gathered? (Select all that apply.)

a. Demographic characteristics
b. Disease characteristics
c. Geographic data
d. Health protection measures taken
e. Length of the disease process
f. When disease struck the area
ANS: A, C, F

The person-place-time model suggests epidemiologists examine demographic characteristics of the
community (person characteristics), geographic or environmental factors (place), and common time factors (time—or when the disease struck). Disease characterstics, health protection measures taken, and
length of the disease process are not used when determining which factors may lead to disease.
Which of the following information must be analyzed to derive an adequate explanation of disease? (Select all that apply.)

a. Description of commonalities among those who became ill
b. Depiction of the possible pathogen
c. Explanation of the health care system in the community
d. Portrayal of the geographic area where people became ill
e. Review of the methods by which disease can be spread
f. Substances that are effective in sanitizing the area described
ANS: A, B, D

The epidemiological triangle includes the agent (pathogen), host (people who are susceptible and become ill), and environment (the geographic area where people became ill). These three areas allow for an
explanation of disease. Explanation of the health care system in the community, review of the methods by which disease can spread, and substances that are effective in sanitizing are not part of examining the
epidemiological triangle.
Which of the following best describes the advantage of the ecosocial epidemiology model over both the web of causation model and the epidemiological triangle model? (Select all that apply.)

a. It decreases the focus on the individual person.
b. It demonstrates the usefulness of molecular epidemiology in disease prevention.
c. It emphasizes the role of complex political and economic context.
d. It is more useful in public policy campaigns in explaining what people need to do
to protect themselves.
e. It reflects the current emphasis on ecology and the environment.
f. Its use suggests possible public policy interventions.
ANS: A, C, F

The ecosocial approach challenges both the individually focused risk factor approach and molecular epidemiology (sequencing of genes to improve individual susceptibility), because it emphasizes the role
of macro-level socioenvironmental factors, especially complex political and economic forces in health
and illness. Molecular epidemiology, the use of public policy campaigns, and the relationship between
ecology and the environment are not advantages of the use of the ecosocial approach.
Which of the following factors are necessary to assume there might be a cause-effect relationship between a particular variable A and a specific illness? (Select all that apply.)

a. It is easy to understand how the variable A could lead to the illness.
b. Research studies consistently demonstrate a relationship between variable A and the illness.
c. The illness is frequently seen without the presence of variable A.
d. The more of variable A present, the sicker the person becomes.
e. Variable A is always found after the person becomes ill.
f. Variable A is never found in the presence of other illnesses.
ANS: A, B, D

There are six criteria for assuming possible causation including strength of the association, dose-response relationship, temporally correct relationship, biological plausibility, consistency among studies, and specificity. Only the "easy-to-understand," consistent research studies and the increased dose leading to
increased illness are consistent with those six criteria.
A nurse wanted a screening test that was very sensitive in determining who might have a particular illness. What might be a problem with using such a sensitive test? (Select all that apply.)

a. Many persons have true negative test results.
b. Persons who test negative are able to celebrate their healthy state.
c. Persons who do not have the illness are told that they might, which leads to anxiety, as well as time and cost of follow-up diagnostic tests.
d. Such a test may have lower specificity, so some persons with the disease are told
they are disease free and hence do not receive care.
e. There is no problem; it is best to use the most sensitive screening test available.
f. Persons who have the disease are notified and receive treatment.
ANS: C, D

The problem with very sensitive tests is that the test picks up almost all people with the disease but also many others who do not have the disease. These "false positives" result in persons needing follow-up
diagnostic tests. Additional time, effort, and expense, as well as worry, result until the negative test results are obtained. There is no problem with persons receiving true negative test results and celebrating that
knowledge or with persons having their condition correctly diagnosed and treated.
Other sets by this creator