Chap. 7: Epidemiology in Community Health Care

A community health nurse is explaining the chain of causation to a family that includes a child who has developed Lyme disease. The nurse correctly describes the opening in the child's skin caused by the actual tick bite as the A) reservoir. B) mode of transmission. C) portal of entry. D) host.

Ans: C Feedback: The opening in the child's skin caused by the actual tick bite is the portal of entry in the chain of causation. The mode of transmission would be the tick biting the child. The reservoir would refer to the tick. The host would be the child who has been bitten by the tick.

After teaching a group of students about the various types of epidemiologic research studies that can be done, the instructor determines that the teaching was effective when the students describe a community trial as which of the following? A) A type of experimental study conducted at the community level B) An inexpensive type of analytic research study C) A study that gathers volunteers for the experimental group D) A way to locate health problems in a variety of communities

Ans: A Feedback: A community trial is conducted as an experimental study design with large populations. Some of the community receives a treatment, while the other part does not. This is probably the most expensive type of experimental study. It involves a great number of subjects, the support of the governmental forces as well as the population involved, a large number of staff over a long period of time, and the cost of the intervention itself. When a whole community is involved, individuals are not approached to be volunteers. What makes it a community study is that the entire community is part of the study. The health problem is identified prior to the implementation of the study. The introduction of an intervention in one community with no introduction in a similar community forms the study population, and the health problem being studied is then monitored between the two populations. The health problem has to be identified first in this type of study.

During which stage of the natural history of a communicable disease would quarantine be most effective? A) Susceptibility stage B) Subclinical disease stage C) Clinical disease stage D) Resolution stage

Ans: A Feedback: Quarantine is the isolation of persons who are susceptible to a communicable disease and have been exposed to that communicable disease until the incubation period of the subclinical disease stage has passed. Quarantining persons during the susceptibility stage itself is not indicated as individuals have not been exposed. The proper action for persons who are in the clinical disease stage and beyond is isolation until the danger of spreading the communicable disease has passed.

A community health nurse is looking for data on the use of nursing home services and the common diagnoses of those using these services. Which source of information would be most appropriate for the nurse to investigate? A) National Center for Health Statistics B) Consumer Product Safety Commission C) Environmental Protection Agency D) Cancer disease registries

Ans: A Feedback: The National Center for Health Statistics furnishes valuable health prevalence data from surveys of Americans. Among the information available is the National Nursing Home Survey, which provides information on those who are using these services and the diagnoses and other characteristics. The Consumer Product Safety Commission and Environmental Protection Agency would provide information about environmental issues. Cancer disease registries would provide information specific to the diagnosis of cancer.

A community health nurse is integrating the epidemiology of wellness into practice. Which of the following would the nurse include? A) Lifestyle with its self-created risks B) Communicable disease control C) The natural history of disease D) Vital statistics and reportable diseases

Ans: A Feedback: Today there is an increased focus on lifestyle behaviors and how they relate to a person's state of wellness or illness. It is a basic component of a wellness model. Communicable disease control focuses on an illness state, not a wellness state, and is not part of a wellness model. The four states of the natural history of a disease or health condition is not part of the wellness model. Vital statistics and reportable diseases are not part of the wellness model.

Which of the following statements about risk is true? Select all that apply. A) Risk is the probability that a disease or unfavorable health condition will develop. B) Risk means that the person who has the most negative influences will definitely develop the disease or unfavorable health condition. C) Risk refers to positive and negative influences on a person's likelihood of developing a specific disease. D) Risk can be measured using the relative risk ratio, which is based on the ratio of incidence in an exposed group to incidence rate in unexposed group. E) Risk is unimportant when determining the most effective points for community health intervention.

Ans: A, C, D Feedback: Risk is the probability that a disease or unfavorable health condition will develop. Risk also refers to positive and negative influences on a person's likelihood of developing a specific disease. Relative risk ratio is a calculation of risk consisting of the ratio of incidence in an exposed group to incidence rate in unexposed group. Risk does not mean that the person who has the most negative influences will definitely develop the disease or unfavorable health condition, but it refers to the probability that the person will develop the disease or unfavorable health condition. The relative risk ratio assists in determining the most effective points for community health intervention in regard to particular health problems.

Which of the following statements apply to the concept of causality? Select all that apply. A) Causality is the relationship between cause and effect. B) The chain of causation is the most recent theory of causality. C) The web of causation theory is the most recent theory of causality. D) The chain of causation clearly explains causation in noninfectious disease. E) Epidemiology has changed its view of causality over time.

Ans: A, C, E Feedback: Causality is the relationship between cause and effect. The web of causation theory is the most recent theory of causality. Epidemiology has changed its view of causality over time. The chain of causation was the first theory of causality. The chain of causation could not sufficiently explain causation in noninfectious disease because the chain of causation is too linear.

The nurse educator knows that a nursing student understands the basics of immunity when the student nurse states A) herd immunity only pertains to cows. B) active immunity can be attained via the use of vaccines. C) passive immunity can be attained via the use of vaccines. D) cross-immunity is immunity that causes a person who is immune to one disease to be also immune to a completely different infectious agent.

Ans: B Feedback: Active immunity can be attained via the use of vaccines. Passive immunity is immunity that is given to a person, either by maternally provided protection for newborn infants or from antibody products that provide temporary resistance. Herd immunity describes the immunity level that is present in a population group. Cross-immunity is immunity that causes a person who is immune to one disease to be also immune to a related infectious agent.

A community health nurse is preparing to carry out an experimental epidemiologic study. Which of the following would be most important for the nurse to do? A) Focus the study on evaluating the cause of a disease B) Ensure carefully controlled conditions during the study C) Expose both groups to the same factor or condition D) Ensure that there are a substantial number of subjects

Ans: B Feedback: Experimental studies are carried out under carefully controlled conditions. In human populations, experimental studies should focus on disease prevention or health promotion rather than testing the cause of disease. The investigator exposes an experimental group to some factor and simultaneously observes a control group similar in characteristics to the experimental group but without the exposure factor. An experimental study need not be elaborate to provide important data.

After a class describing the contributions of Florence Nightingale to epidemiology, the instructor determines that the class needs additional instruction when they state which of the following is associated with Nightingale? A) Establishment of the need for a clean environment B) A sophisticated coding system for medical conditions C) Proper wound cleansing and bandaging techniques D) Separation of infected individuals from those injured

Ans: B Feedback: Nightingale's colleague, William Farr, is credited for developing a more sophisticated system for coding medical conditions. Nightingale's contributions included establishing the need for a clean environment, properly cleaning wounds and bandaging them, and separating infected soldiers from those who were injured.

An instructor is discussing the worldwide distribution of AIDS. Which term would the instructor use to describe this situation? A) Epidemic B) Pandemic C) Endemic D) Pathogenicity

Ans: B Feedback: Pandemic is the term used to describe an epidemic that is distributed worldwide. An epidemic refers to a disease occurrence that clearly exceeds the normal or expected frequency in a community or region. Endemic is used to describe the continuing presence of a disease or infectious agent in a given geographic area. Pathogenicity refers to an agent's capacity to cause disease in a host.

While visiting a family's home, the community health nurse finds out that the two children in the home were exposed to chickenpox. Assessment of the children reveals no signs of fever or lesions. The nurse determines that the children may be in which stage of the disease? A) Susceptibility B) Subclinical disease C) Clinical disease D) Resolution

Ans: B Feedback: The children have been exposed but have not yet developed the signs of chickenpox. Therefore, they are in the subclinical disease stage. During the susceptibility stage, the disease is not present and individuals have not been exposed. During the clinical stage, signs and symptoms are beginning to develop. During the resolution stage, the disease causes sufficient anatomic or functional changes to produce recognizable signs and symptoms.

The nurse is examining the possibility that multiple factors are involved in the development of a disorder. The nurse is applying which of the following? A) Chain of causation B) Web of causation C) Strength of association D) Temporality

Ans: B Feedback: The web of causation is being used to apply the concept of multiple causes to explain the existence of health and illness states. It was a refinement of the chain of causation, such that it looked at the combination of multiple factors as implicated in the development of poor outcomes. The chain of causation focuses on one factor in the development of a condition. The strength of association is an element of causation in noninfectious disease that refers to the ratio of disease rates in those with and without the causal factor. Temporality, also involved with the causation of noninfectious disease, is an element in which the exposure to the suspected factor must precede the onset of the disease.

Which of the following is true about incidence and prevalence? Select all that apply. A) Prevalence is the number of new cases of a disease or health condition. B) Incidence is the number of new cases of a disease or health condition. C) Prevalence refers to all of the people with a particular health condition existing in a given population at a given point in time. D) Incidence refers to all of the people with a particular health condition existing in a given population at a given point in time. E) When determining if a disease is endemic in a specific area, the statistic that is most helpful is prevalence.

Ans: B, C, E Feedback: Incidence is the number of new cases of a disease or health condition. Prevalence refers to all of the people with a particular health condition existing in a given population at a given point in time. When determining if a disease is endemic in a specific area, the statistic that is most helpful is prevalence.

Organize the following steps in the epidemiologic study from the first step to the last. A) Collect the data. B) Identify the problem. C) Analyze the findings. D) Disseminate the findings. E) Review the literature. F) Develop conclusions and applications. G) Design the study.

Ans: B, E, G, A, C, F, D Feedback: The proper order of the steps in the epidemiologic study from the first step to the last is to identify the problem, review the literature, design the study, collect the data, analyze the findings, develop conclusions and applications, and disseminate the findings.

The nurse is reviewing a research article that describes the use of the bacille Calmette-Guerin (BCG) vaccine to prevent tuberculosis that was given to individuals who were exposed to leprosy. The individuals did not develop the leprosy. The nurse interprets this as most accurately demonstrating which type of immunity? A) Herd immunity B) Passive immunity C) Cross-immunity D) Active immunity

Ans: C Feedback: Cross-immunity refers to a situation in which a person's immunity to one agent provides immunity to a related agent as well. This immunity can be active or passive. Herd immunity describes the immunity level present in a population group. Passive immunity refers to short-term resistance acquired naturally or artificially. Active immunity is long-term and can be acquired naturally or artificially.

When implementing an epidemiologic research study, which of the following would the community health nurse complete as the final step? A) Analyze the data B) Design the study C) Disseminate findings D) Review the literature

Ans: C Feedback: The last step in the research process is to disseminate the findings. After identifying the problem and reviewing the literature, the researcher designs the study, collects the data, analyzes the findings, and develops conclusions and applications.

When applying the epidemiologic triad model to a community's plan of care, which of the following would the community health nurse address? A) Incidence, prevalence, and case fatality B) Health, illness, and injury C) Host, agent, and environment D) Immunity, causation, and risk

Ans: C Feedback: The purpose of this model is to demonstrate the relationship among host, agent, and environment. Each component has to be present to a certain degree in order for any disease, illness, or injury to exist or happen. If one component is missing, illness or injury will not occur. Incidence, prevalence, case fatality, health, illness, injury, immunity, causation, and risk are terms used in epidemiology but do not refer to the epidemiologic triad model.

The nurse is reviewing actual census data for information for use in an epidemiologic study. Which of the following would the nurse be least likely to find? A) Occupational status B) Housing quality C) Births recorded D) Educational level

Ans: C Feedback: Vital statistic data provides information about the number of births recorded. Census data includes information about age, sex, race, ethnic background, type of occupation, income gradient, marital status, educational level, and other standards such as housing quality. If the nurse is reviewing actual census data, the nurse would be least likely to find births recorded, which is vital statistics.

When assessing several populations, the nurse notes each population's relative risk. Using the relative risk ratios below, which population would require a major emphasis for risk reduction intervention? A) 0.59 B) 1.13 C) 1.79 D) 2.45

Ans: D Feedback: A relative risk >1.0 indicates that those with the risk factor have a greater likelihood of acquiring the disease than do those without it. For example, a relative risk ratio of 2.45 means that the exposed group is 2.45 times more likely to acquire the disease than the unexposed group. Therefore, interventions to reduce this population's risk would be most important.

A community health nurse is participating in a caseñcontrol observational study. Which of the following would most likely explain this type of study? A) Description of patterns of occurrence of illness and injury in a population B) Investigation of development of healthñillness conditions over a long period of time C) Studying of a cohort with evaluation of variables associated with the disease or injury D) Comparison of persons with and without a healthñillness condition

Ans: D Feedback: Comparing persons with and without a certain condition is known as a caseñcontrol study. A study that describes patterns of occurrence in a population is a descriptive study. Following people over a long period of time is a longitudinal study. And cohorts are groups studied over time.

Which of the following would the community health nurse identify as a key component of the host? A)Infectivity B) Antigenicity C) Virulence D) Inherent resistance

Ans: D Feedback: The host, a susceptible human or animal, can sometimes have an ability to resist pathogens. This is called inherent resistance. Infectivity, antigenicity, and virulence are characteristics of the agent.

When using descriptive epidemiology, which type of study would the community health nurse expect to include? A) Prevalence study B) Case-control study C) Cohort study D) Count study

Ans: D Feedback: Descriptive epidemiology includes investigations that seek to observe and describe patterns of health-related conditions that occur naturally in a population. The simplest measure of a description is a count. Prevalence, caseñcontrol, and cohort studies are types of studies involved with analytical research.