Quiz 4

The nurse reviews a published analytical research study that compares one group of clients who developed diabetes mellitus before the start of the study with a group of clients without diabetes mellitus. Which type of study design was used in this study? A) Case control B) Case C) Clinical trial D) Cohort

Ans: A Feedback: A case-control study is an observational analytic study that enrolls one group of persons with a certain health problem (case-clients) and a group of persons without the health problem (control subjects). It compares differences in exposures, behaviors, and other characteristics to identify and quantify associations, test hypotheses, and identify causes. A case study is a research method that involves an in-depth analysis of an individual, group, or institution. A clinical trial is an experimental study in which the investigator specifies the type of exposure for each study participant and then follows each person's health status to determine the effects of the exposure. A cohort study is an observational analytic study in which enrollment is based on the status of exposure to a certain factor or membership in a certain group.

Which correctly defines an adjusted rate? A) Statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another B) Measure of the probability that people without a certain condition will develop that condition over a period of time C) Measure of the number of people in a given population who have an existing condition at a given point in time D) Detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator

Ans: A Feedback: Adjusted rate is the statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another. Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time. Prevalence rate is the measure of the number of people in a given population who have an existing condition at a given point in time. Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator. Often people are divided into subgroups by age and sex, although any characteristic can be used.

A client with tuberculosis sneezes in the waiting room and infects several other clients who are sitting on the other side of the room. Which mechanism of transmission is involved in this case? A) Airborne B) Droplet C) Direct contact D) Indirect contact

Ans: A Feedback: Airborne transmission occurs when microorganisms are carried in the air in small particles, called droplet nuclei, at distances that exceed a few feet. Droplet transmission theoretically is a form of contact transmission; the mechanism of transfer of the pathogen to the host is quite distinct from either direct or indirect transmission. Therefore, droplet transmission is considered a separate route of transmission. Droplets are generated from the source person primarily during coughing, sneezing, or talking and are propelled a short distance (<3 feet) through the air and deposited on the conjunctivae, nasal mucosa, or mouth of another person. Direct contact occurs through direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonized person (or animal). Indirect contact involves contact of a susceptible host with a contaminated intermediate inanimate object, called a vehicle, such as a contaminated surgical instrument, needle, toy, soiled clothing, or bed linen.

The client reports diarrhea, fever, and abdominal cramps 24 hours following exposure to raw eggs while cooking. An efficient and effective homemade oral rehydration solution is to stir: A) One level teaspoon of salt and eight level teaspoons of sugar into one quart or liter of clean drinking water B) Eight level teaspoons of salt and one level teaspoon of sugar into one quart or liter of clean drinking water C) One level teaspoon of salt and one level teaspoon of sugar into one quart or liter of clean drinking water D) Eight level teaspoons of salt and eight level teaspoons of sugar into one quart or liter of clean drinking water

Ans: A Feedback: An efficient and effective homemade oral rehydration solution is to stir one level teaspoon of salt and eight level teaspoons of sugar into one quart or liter of clean drinking water or water that has been boiled and cooled.

Chloroquine-resistant malaria occurs in most of Africa, the Middle East, and Asia and all of the South Pacific islands. This type of disease occurrence is known as: A) Endemic B) Epidemic C) Pandemic D) Outbreak

Ans: A Feedback: An endemic disease, infection, or infectious agent occurs when it becomes prevalent within a population or geographic area. An epidemic or outbreak refers to a significant increase in an infection or infectious disease beyond the expected (endemic) level in a certain population and/or geographic area. A pandemic is an epidemic that generally spreads worldwide. The use of "outbreak" in this text is synonymous with epidemic.

The nurse graphs the distribution of influenza cases by the time of onset of influenza. Which would be the result of this work? A) Epidemic curve B) Epidemiologic descriptive study C) Incidence density D) Incidence rate

Ans: A Feedback: An epidemic curve is a graph that plots the distribution of cases by the time of onset of the disease. Epidemiologic descriptive studies are research studies designed to acquire more information about the occurrence and distribution of states of health, such as characteristics of person, place, and time. Incidence density is the use of a person-time denominator in the calculation of rates. A person-day reflects one person at risk for 1 day, and a person-year represents one person at risk for 1 year. Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time

A client presents with severe diarrhea. The client tells the nurse that she went to a chicken roast at church the previous weekend. The nurse suspects a foodborne illness. Which cause of bacterial foodborne illness should the nurse most suspect in this case? A) Campylobacter B) Listeria monocytogenes C) Salmonella D) Escherichia coli O157:H7

Ans: A Feedback: Campylobacter is the most common cause of bacterial foodborne illness in the United States, and it is an important cause of diarrheal illness throughout the world regardless of people's age. Consumption of contaminated poultry is the most common source of Campylobacter infection, although undercooked meats, ground beef, pork, cheese, eggs, shellfish, unpasteurized milk, and direct exposure to pets and farm animals have been implicated. Other infectious organisms that commonly cause foodborne illnesses include noroviruses, Listeria monocytogenes, nontyphoid Salmonella, and E. coli O157:H7.

The nurse conducts a study that will follow a group of subjects for two decades. It involves one group of subjects who have a risk factor for developing diabetes and another group who do not have a risk factor. The goal is to establish a cause-and-effect relationship between the existence of the risk factor and the occurrence of diabetes. Which study design would be most appropriate? A) Cohort B) Case-control C) Preventive D) Therapeutic

Ans: A Feedback: Cohort studies, sometimes referred to as longitudinal studies, are prospective studies that monitor subjects over time to find associations between risk factors and health outcomes. In their simplest form, a sample (cohort) of subjects who are exposed to the risk factor(s) is matched with a sample of subjects not exposed to the risk factor. Cohort studies attempt to find cause-and-effect relationships. Case-control studies, also known as retrospective studies, work backward from the effect to the suspected cause. Subjects are selected on the basis of the presence or absence of the disease or outcome in question: one group of people (case-subjects) with the health problem and another group without the health problem (controls). The two groups are then compared to determine the presence of specific exposures or risk factors. A preventive study is focused on preventing the occurrence of disease in subjects. Therapeutic trials are based on secondary prevention, which focuses on limiting the spread of disease, and where the treatment (independent variable) is manipulated by the researcher.

he nurse is responsible for the construction of an isolation unit during an H5N1 outbreak. The unit is designated for only those clients with a confirmed diagnosis of H5N1. Which unit would be easily adapted to client needs? A) 12-room unit with negative air pressure units B) 15-room unit with a portable supply of PPEs C) 8-room unit with four code carts D) 12-room unit with four to six air changes per hour

Ans: A Feedback: For an outbreak of H5N1, place the client in an airborne isolation room (AIR). Such rooms should have monitored negative air pressure in relation to the corridor, with 6 to 12 air changes per hour (ACH), and exhaust air directly outside or have recirculated air filtered by a high-efficiency particulate air (HEPA) filter. If an AIR is unavailable, a portable HEPA filter should be used to augment the number of ACH. Use a fit-tested respirator, at least as protective as a National Institute of Occupational Safety and Health (NIOSH)-approved disposable N-95 filtering face piece respirator, when entering the room (DHHS, 2006). The Centers for Disease Control and Prevention (CDC) has recommended nonpharmaceutical community interventions that use social distancing strategies to reduce contact between people.

Who is considered the first epidemiologist? A) Hippocrates of Cos B) Aretaeus the Cappadocian C) Claudius Galen D) Susruta

Ans: A Feedback: Hippocrates of Cos was the first to record the relationship of the external environment to the health of individuals and is considered the first epidemiologist. Aretaeus the Cappadocian described pulmonary tuberculosis in detail. Claudius Galen described the four humors, introduced many drugs derived from plants, and was the first to describe smallpox. Susruta was a Brahmin physician who associated malaria with the mosquito.

Over the course of a year, there were 42 cases of institution-associated pneumonia at a hospital. During that time, 3,102 clients were at risk for acquiring this infection, covering a total of 20,411 client-days. Which is the client density in terms of number of cases per 1,000 client-days at this hospital during this time? A) 2.1 B) 13.5 C) 15.2 D) 152

Ans: A Feedback: Incidence density is calculated by dividing the number of new cases occurring during the study period by the person-time units accumulated by subjects during the study period and multiplying the result by the base multiple of 10. In this case, the following equation would result: 42/20,411 = 0.0021 × 1,000 = 2.1 cases per 1,000 client-days.

The nurse wishes to measure the number of cases of staph infections that occur in a hospital over the course of 1 year per total client-days during that year. Which measure should the nurse use? A) Incidence density B) Prevalence rate C) Relative risk ratio D) Specific rate

Ans: A Feedback: Incidence density is the use of a person-time denominator in the calculation of rates. A person-day reflects one person at risk for 1 day, and a person-year represents one person at risk for 1 year. Prevalence rate is the measure of the number of people in a given population who have an existing condition at a given point in time. Relative risk ratio is the ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group. Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator.

The nurse is conducting a study on how regular physical activity affects the risk for developing lung cancer among smokers. One group leads a sedentary lifestyle whereas the other has agreed to undergo regular supervised exercise in the gym of a local hospital. During the study, the sole treadmill in the gym broke down and was unable to be used for the last half of the study. Several study participants who preferred the treadmill to other machines did not exercise as long or as intensely as they might otherwise have. Which threat to the external validity of the study does this represent? A) Interaction of history and intervention B) Interaction of selection and intervention C) Experimenter/participant effect D) Novelty

Ans: A Feedback: Interaction of history and intervention occurs when the circumstances of the study influence the results of the study, decreasing the generalizability of the findings. Such is the case with the broken treadmill that potentially decreased the participant's overall exercise volume. Interaction of selection and intervention occurs when subjects willing to participate in the study are not representative of the target population, thus limiting the generalizability of the results. Experimenter/participant effect occurs when the researcher has preconceived expectations of the intervention, resulting in bias and affecting the generalizability of the findings. Novelty occurs when a new intervention affects the outcome of the study because of either enthusiasm or skepticism by the researchers or the participants.

A client wants to know the best way to avoid sexually transmitted infections (STIs). The nurse should mention: A) Abstinence B) Monogamous relationship with an infected partner C) Washing the genitals after sex D) Use of latex condoms

Ans: A Feedback: Other than abstinence, a long-term mutually monogamous relationship with a partner who has been tested and is known to be uninfected is the best way to avoid STIs. Sexual partners should talk to each other about their STIs so that preventive action can be taken. Prevention of STI transmission does not include washing the genitals, urinating, or douching after sex. Latex condoms can reduce the risk of transmission but only when used consistently (every time) and correctly.

Which is the primary method used to measure the existence of states of health or illness in a population during a given time period? A) Rate B) Ratio C) Relative risk ratio D) Sensitivity

Ans: A Feedback: Rate is the primary measurement used to describe the occurrence (quantity) of a state of health in a specific group of people in a given time period. Ratio is a fraction that represents the relationship between two numbers. Relative risk ratio is the ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group. Sensitivity is the ability of a test to correctly identify people who have a health problem or the probability of testing positive if the health problem is truly present.

In reviewing a study that considered the sensitivity of a particular screening test for HIV, the nurse found 21 true positives, 853 true negatives, 3 false positives, and 5 false negatives. What is the sensitivity of this test? A) 80.8% B) 87.5% C) 93.7% D) 99.6%

Ans: A Feedback: Sensitivity is calculated by dividing the number of true positives by the sum of the number of true positives and false negatives. In this case, the sensitivity would be calculated as follows: 21/21 + 5 = 21/26 = 0.808 = 80.8%.

The nurse is preparing a research study on the number of heart attacks in the community and the number of individuals who are actively involved in exercise programs following a heart attack. Using knowledge of research study design, which gold standard for a research design should be considered? A) Randomized, control group B) Quasi-experimental C) Experimental D) Descriptive epidemiologic

Ans: A Feedback: The "gold standard" for experimental studies is the prospective, double-blind, placebo-control group design, also referred to as clinical trials or therapeutic trials. In double-blind experimental studies, neither the researchers nor the subjects are aware to which group they are randomly assigned. Quasi-experimental and experimental designs are used to examine causality. Many studies, although experimental in design, are not able to either randomize selection of subjects or exert the same degree of control of the study variables that would be found in true experimental studies. Descriptive epidemiologic studies, which are frequently used in public health, are designed to acquire more information about characteristics of health (or disease) as they pertain to person, place, and time. Findings from descriptive epidemiologic studies lead to hypotheses for future research.

In researching cases of West Nile virus in the community, the nurse explores how the interactions among people infected with this virus, mosquitoes, and the environment they share contribute to outbreaks of this disease. Which epidemiologic model is used in this case? A) Epidemiologic triad B) Wheel of causation C) Web of causation D) Natural history

Ans: A Feedback: The epidemiologic triad is the classic model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment, not by any single factor. The wheel of causation de-emphasizes the agent as the sole cause of disease while emphasizing the interplay of physical, biological, and social environments. The web of causation is an epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness. Natural history is the course of a disease or condition from the onset to Resolution.

Which was the leading cause of death in the United States in 1900? A) Major cardiovascular-renal disease B) Influenza and pneumonia C) Tuberculosis D) Gastritis, duodenitis, enteritis, and colitis

Ans: A Feedback: The leading cause of death in 1900 was major cardiovascular-renal disease followed by influenza and pneumonia; tuberculosis; and gastritis, duodenitis, enteritis, and colitis.

Who in the history of epidemiology developed mortality surveillance systems, addressed basic epidemiologic concepts, and is considered the founder of modern statistics? A) William Farr B) John Graunt C) Florence Nightingale D) John Snow

Ans: A Feedback: William Farr is considered the father of modern statistics. John Graunt analyzed weekly reports of births and deaths. Florence Nightingale used statistics to improve public health in England. John Snow performed epidemiologic research on transmission of cholera using natural experiments, mapping, and rates.

A client arrives on the unit, diagnosed with norovirus infection from eating shellfish. The client has been vomiting repeatedly and is now severely dehydrated. Which interventions are likely to be performed for this client? (Select all that apply.) A) Starting an intravenous line for fluid and electrolyte replacement B) Encouraging the client and the client's family to practice good handwashing C) Immediate disinfecting all potentially contaminated objects and surfaces D) Isolating the client until 12 hours after the client has been symptom free E) Administering a vaccination

Ans: A, B, C Feedback: Oral hydrating solutions should be given for attacks of norovirus, and in severe cases intravenous fluid and electrolyte replacement may be necessary. At the first signs of this acute gastroenteritis outbreak, good handwashing, thorough and immediate disinfection with appropriate solutions, and isolation of sick people until 72 hours, not 12 hours, after they are symptom free are critical. There is no vaccine currently for noroviruses.

As the occupational health nurse in a factory finds that five employees out of 30 have positive tuberculin skin test results. One employee on the 3-to-11 shift has been diagnosed with active tuberculosis (TB). She asks if this means that the whole factory has been exposed. The nurse replies that the probability of infection depends upon: (Select all that apply.) A) Concentration of infectious droplet nuclei in the air B) Duration of exposure to the infected person C) Proximity to the infected person D) The use of safety gloves by employees E) Physical exertion required in the job

Ans: A, B, C Feedback: The probability that a person who is exposed to Mycobacterium tuberculosis will become infected depends primarily on the concentration of infectious droplet nuclei in the air and the duration of exposure to a person with infectious TB disease. The closer the proximity and the longer the duration of exposure, the higher the risk of becoming infected. Close contacts are people who share the same air space in a household or other enclosed environment for a prolonged period (days or weeks, not minutes or hours) with a person with pulmonary TB disease. A suspected TB client is a person in whom a diagnosis of TB disease is being considered, whether anti-TB treatment has been started. People generally should not continue to be suspected of having TB for more than 3 months. The use of safety gloves and physical exertion on the job do not affect the probability of infection.

The nurse has been requested to investigate the outbreak of H1N1 in the community. In documenting the outbreak, which should be included in its description? Select all that apply. A) The names of all people who have been infected by the virus B) The geographical area within which the outbreak has occurred C) A brief history of all of the other viral outbreaks that have occurred in the community in recent years D) The time of onset and duration of the outbreak E) The anticipated economic impact of the outbreak on the community

Ans: A, B, D Feedback: The nurse should describe the outbreak according to person, place, and time. A history of other viral outbreaks and the economic impact of the outbreak are not necessary for the nurse to document.

The nurse is in charge of the flu vaccination program in the community. Which actions should the nurse take when planning and evaluating this program? Select all that apply. A) Measure epidemiologic statistics before and after administering the flu shots. B) Plan and evaluate influenza vaccinations regularly. C) Interview clients regarding their perception of the effectiveness of the vaccinations and use these data in planning future vaccinations. D) As new data regarding influenza vaccinations become available, modify the intervention accordingly. E) Evaluate the success of your program by comparing its results with those in other communities.

Ans: A, B, D Feedback: The primary way to demonstrate prevention or control of a health problem is to compare epidemiologic statistics before and after the implementation of the health service. Planning and evaluation are continuous processes. As new data become available, modification in health services may be necessary, and those modifications require evaluation. Evaluation of the program and planning of future interventions should not be based on the clients' perception of its effectiveness, which is likely to not be accurate. Because factors may vary significantly from community to community, it would be more appropriate to compare before and after statistics in your own community rather than statistics with other communities.

A nurse is studying the Institute of Medicine's convergence model to learn how four types of interrelated and overlapping microbe-human interactions can lead to emerging/reemerging infectious diseases. These four types of interactions are: (Select all that apply.) A) Genetic and biological B) Physical/environmental C) Spiritual and psychological D) Ecological E) Social, political, and economic

Ans: A, B, D, E Feedback: There are four types of interrelated and overlapping microbe-human interactions that can lead to emerging/reemerging infectious diseases: (1) genetic and biological; (2) physical/environmental; (3) ecological; and (4) social, political, and economic. Spiritual and psychological are not types of interactions leading to infectious diseases

In infectious disease epidemiology, just the presence of an infectious agent is not sufficient to produce an infectious disease. Which host factors determine whether a person is at risk for an infection or an infectious disease? (Select all that apply.) A) Age B) Sex C) Occupation D) Physical and emotional health E) Immune status

Ans: A, B, D, E Feedback: There are several host factors that determine whether a person is at risk for an infection or an infectious disease. These include age, sex, race, physical and emotional health, and immune status. Occupation is not a host factor.

The nurse prepares to enter the room of a client with suspected Ebola virus disease (EVD). Which pieces of personal protective equipment (PPE) should the nurse wear? (Select all that apply.) A) Fluid-resistant gown B) Gloves C) Respirator D) Mask E) Goggles

Ans: A, B, D, E Feedback: When entering the room of a client with or suspected EVD, all healthcare providers should wear PPE, including a fluid-resistant gown, gloves, mask, and face shield/goggles (CDC, Infection prevention and control recommendations for hospitalized clients with known or suspected Ebola in U.S. hospitals). A respirator is not necessary.

The nurse is responsible for the directly observed therapy (DOT) program in the community. Which represent the best methods to ensure compliance with clients' drug regimens? (Select all that apply.) A) Social service support B) Housing assistance C) Hospitalization D) Isolation until treatment complete E) Treatment enablers

Ans: A, B, E Feedback: Programs using DOT as the central element in a comprehensive, client-centered approach to case management (enhanced DOT) have higher rates of treatment completion than less intensive strategies. Each client's management plan should be individualized to incorporate measures that facilitate adherence to the drug regimen. Such measures may include, for example, social service support, treatment incentives and enablers, housing assistance, referral for treatment of substance abuse, and coordination of TB services with those of other providers. There is no need to hospitalize a person solely because he or she is infectious. Outclients should be instructed to remain at home, without visitors, until they are no longer thought to be infectious. However, such isolation is not a method to ensure compliance with the drug regimen but an infection control measure.

Tent communities are constructed in a rural community by the American Red Cross after a disaster. Because of overcrowding, surrounding states create accommodations for the displaced and homeless. The survivors are accommodated in the cities of four Southern states. Which factors may increase the possibility of disease emergence in the cities? (Select all that apply.) A) Poor hygiene B) Decreased socialization C) Poor sanitation D) Decreased viral load E) Increased violence

Ans: A, C Feedback: Urban life, with malnutrition, overcrowding, and poor sanitation, enhances the major pathways for transmission of infectious disease. The forced dislocation of large groups of people and migration of such groups of people from rural areas to cities can be accompanied by a breakdown of public health measures, leading to poor hygiene. These have often been factors in disease emergence. Decreased socialization, decreased viral load, and increased violence would not tend to increase the likelihood of disease emergence.

The nurse is measuring the occurrence of chronic obstructive pulmonary disease being investigated in the entire population. Which rate does this represent? A) Adjusted B) Attack C) Crude D) Incidence

Ans: C Feedback: Crude rate is the measurement of the occurrence of the health problem or condition being investigated in the entire population. Adjusted rate is the statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another. Attack rate is the incidence or occurrence rate. Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time.

The nurse is conducting a cross-sectional study of people who are HIV positive and their exposure to certain risk factors. Given the nature of this type of study, which would be true? (Select all that apply.) A) Respondents are a sample that represents the entire population. B) The results of the study will allow determination of cause and effect. C) Data represent a point in time. D) Data are gathered via a questionnaire or interview. E) Subjects are randomly assigned to treatment and control groups.

Ans: A, C, D Feedback: Cross-sectional studies (prevalence studies) are an example of public health survey research. Survey research focuses on the collection of information regarding the status quo of some situation(s) by questionnaire or by interviews with a sample of respondents. The main principle of survey research is that the sample of respondents must represent the population from which it was drawn. In this type of study, the population to be studied is defined, and data are collected from members of the group about their disease and exposure status. The data represent a point in time; therefore, they provide a "snapshot" of the population. Cross-sectional studies are good for examining the relationship between a variable and a disease/condition but not for determining cause and effect, which requires the collection of data over time. Subjects are randomly assigned to treatment and control groups in randomized, control group intervention studies, not in cross-sectional studies.

Which environmental factors are likely to affect the life cycle of disease pathogens and their vectors and thus disease outbreaks? (Select all that apply.) A) Temperature B) Geology C) Precipitation D) Humidity E) Amount of daylight

Ans: A, C, D Feedback: Many infectious diseases have characteristic geographic distributions and seasonal variations. Probably the most common is the influenza virus, which peaks each fall and winter. Factors such as temperature, precipitation, and humidity affect the life cycle of many disease pathogens and their vectors, and consequently they can affect disease outbreaks. Geology, or the types of rocks present in the area, and the amount of daylight are not likely to affect the life cycle of disease pathogens and their vectors.

Infectious agents are biological agents capable of producing an infection or infectious disease. Which are considered biological agents? (Select all that apply.) A) Fungi B) Fomites C) Bacteria D) Viruses E) Helminths

Ans: A, C, D, E Feedback: Infectious agents are biological agents capable of producing an infection or infectious disease and include bacteria, viruses, rickettsiae, fungi, protozoa, and helminths. Fomites are any substance that adheres to and transmits infectious materials. An infectious disease need not be contagious or communicable.

Advantages of a case-control study include: (Select all that apply). A) Allows for the examination of multiple exposures for a single outcome B) Allows for the direct measure of the incidence of a disease C) Is generally quicker and less expensive to conduct than cohort studies D) Appropriate for studying rare exposures E) Requires fewer case-subjects

Ans: A, C, E Feedback: Case-control studies have several advantages: they allow for the examination of multiple exposures for a single outcome, are suitable for studying rare diseases and those with long latency periods, require fewer case-subjects, and generally are quicker and less expensive to conduct than cohort studies, making them well suited for an outbreak investigation. They have several disadvantages: they are not appropriate for studying rare exposures, they are subject to bias because of the method used to select controls, and they do not allow the direct measure of the incidence of disease.

Which factors place an individual at high risk for acquiring a sexually transmitted infection (STI)? (Select all that apply.) A) Having multiple sexual partners B) Using a condom during sex C) Having no other STIs D) Having a sexual partner who has had an STI E) Receiving a blood transfusion

Ans: A, D Feedback: Any person is in a high-risk group for STIs if they have multiple sexual partners, do not use a condom during sex, have other STIs, and/or have a sexual partner who has had an STD. Although once a risk for exposure to HIV, blood transfusions no longer place an individual at high risk for acquiring an STI.

The nurse reviews published research studies on clients with developmental disabilities who receive music therapy once a week. Using knowledge of research studies, what type of research study would entail an in-depth analysis of one group of developmentally disabled individuals and the effects of music therapy? A) Case control B) Case C) Clinical trial D) Cohort

Ans: B Feedback: A case study is a research method that involves an in-depth analysis of an individual, group, or institution. A case-control study is an observational analytic study that enrolls one group of persons with a certain health problem (case-clients) and a group of persons without the health problem (control subjects). It compares differences in exposures, behaviors, and other characteristics to identify and quantify associations, test hypotheses, and identify causes. A clinical trial is an experimental study in which the investigator specifies the type of exposure for each study participant and then follows each person's health status to determine the effects of the exposure. A cohort study is an observational analytic study in which enrollment is based on the status of exposure to a certain factor or membership in a certain group.

Which best describes a prospective study? A) Descriptive study in which participants are enrolled before the health outcome of interest has occurred B) Analytic study in which participants are enrolled before the health outcome of interest has occurred C) Descriptive study in which participants are enrolled after the health outcome of interest has occurred D) Analytic study in which participants are enrolled after the health outcome of interest has occurred

Ans: B Feedback: A prospective study is an analytic study in which participants are enrolled before the health outcome of interest has occurred. A retrospective study is an analytic study in which participants are enrolled after the health outcome of interest has occurred.

Who first described pulmonary tuberculosis in detail? A) Hippocrates of Cos B) Aretaeus the Cappadocian C) Claudius Galen D) Susruta

Ans: B Feedback: Aretaeus the Cappadocian described pulmonary tuberculosis in detail. Hippocrates of Cos was the first to record the relationship of the external environment to the health of individuals. Claudius Galen described the four humors, introduced many drugs derived from plants, and was the first to describe smallpox. Susruta was a Brahmin physician who associated malaria with the mosquito.

The clinic clients respond negatively to the need for a yearly flu shot. They ask why the medical communities don't just create one shot that will last for several years. Which explanation should the nurse give? A) Genetic changes in the bacteria that cause the flu require a rotating course of antibiotics. B) Genetic changes make the flu virus resistant to the flu shot from year to year. C) There is more than one strain of the flu virus and you must be protected from all of them. D) The shots last only for 3 to 6 months and must be renewed on a yearly basis.

Ans: B Feedback: As microbes reproduce, genetic changes may result in pathogens that are immunologically distinct from their parental strains. For example, antigenic drift, the slow and progressive genetic changes that take place in DNA and RNA as organisms replicate in multiple hosts, causes changes in influenza viruses each year. These frequent changes that result from antigenic drift mean that there is a new seasonal influenza vaccine each year. The flu is caused by the influenza virus, not bacteria, so antibiotics would not be appropriate for treatment. One does not need to be protected from all strains of the flu virus, only the ones prevalent in the client's area at the present time. Vaccination shots typically last for years, not for 3 to 6 months.

The nurse wishes to determine how many people in the city die from heart attacks each year per 100,000 population. Which type of rate is the nurse attempting to calculate? A) Age-specific mortality rate B) Cause-specific mortality rate C) Case fatality rate D) Crude mortality rate

Ans: B Feedback: Cause-specific mortality rates indicate the probability of death from a specific cause; the number of deaths from a specific disease is divided by the number of people in the population at midyear and multiplied by 100,000. Age-specific mortality rates indicate the probability of death among those of a specific age group; the number of deaths in the age group is divided by the number of people in that age group in the population at midyear and multiplied by 100,000. In calculating the case fatality rate, the number of people with a specific disease such as lung cancer becomes the subgroup being studied out of the entire population in a designated geographic area. Crude mortality rate is simply the number of deaths occurring in 1 year divided by the midyear population and multiplied by 100,000.

Over the course of a year, there were 42 cases of institution-associated pneumonia at a hospital. During that time, 3,102 clients were at risk for acquiring this infection, with 20,411 client-days. Which is the crude incidence rate of institution-associated pneumonia at this hospital? A) 0.21% B) 1.35% C) 1.52% D) 15.20%

Ans: B Feedback: Crude incidence rate is calculated by dividing the number of occurrences or cases of a health problem by the number of people in the population who are at risk for the health problem. In this case, the following equation would result: 42/3,102 = 0.0135 = 1.35%.

Which occurs in the epidemiologic process that is similar to the implementation phase of the nursing process? A) Data are gathered from reliable sources B) Actions are initiated to carry out the plan C) Actions are evaluated and report prepared D) Further research is conducted if necessary

Ans: B Feedback: During the implementation phase of the epidemiologic process, actions are initiated to implement the plan. During the assessment phase of the epidemiologic process, data are gathered from reliable sources. During the evaluation phase of the epidemiologic process, actions are evaluated, a report is prepared, and further research is conducted if necessary.

Three years after exposure to a virulent form of the flu, a population faces the same flu strain. The public health department recognizes that there are members of the population who have not been exposed to the flu strain. Which is most likely to happen? A) The unexposed population will contract the illness B) The unexposed population is not likely to contract the illness C) The unexposed population will contract the illness and reinfect others D) The flu will reach epidemic proportions and both populations will become ill

Ans: B Feedback: If a substantial proportion of people in a population are not susceptible to a communicable disease, the few people who are susceptible are not likely to be exposed and contract the illness. This is a process called herd immunity.

The nurse wishes to calculate the probability of persons in your county developing chronic obstructive pulmonary disease over the course of a year. Which measure should the nurse use? A) Incidence density B) Incidence rate C) Relative risk ratio D) Specific rate

Ans: B Feedback: Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time. Incidence density is the use of a person-time denominator in the calculation of rates. A person-day reflects one person at risk for 1 day, and a person-year represents one person at risk for 1 year. Relative risk ratio is the ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group. Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator.

Who was one of the first people to study patterns of disease in populations and analyzed the weekly reports of births and deaths in London, the results of these analyses becoming the precursor of modern vital statistics? A) William Farr B) John Graunt C) Florence Nightingale D) John Snow

Ans: B Feedback: John Graunt analyzed weekly reports of births and deaths. William Farr is considered the father of modern statistics. Florence Nightingale used statistics to improve public health in England. John Snow performed epidemiologic research on transmission of cholera using natural experiments, mapping, and rates.

Several levels of public health surveillance are necessary to protect the nation's health. At what level are healthcare providers and health facilities required to report certain infectious diseases? A) Local B) State C) Federal D) International

Ans: B Feedback: Local reporting mechanisms are community specific. At the state level, healthcare providers and health facilities are required to report certain infectious diseases to state health departments. At the federal level, the Department of Health and Human Services (DHHS) is the US public health infrastructure that develops policies to protect the nation's health. The Centers for Disease Control and Prevention (CDC) also is a partner with the World Health Organization (WHO) through the Global Outbreak Alert and Response Network and the WHO Surveillance and Response system, which provide international epidemic alerts and responses.

The nurse wishes to conduct research on the number of cancer clients who are actively involved in exercise programs following chemotherapy. To prepare, the nurse reviews similar, published research studies. The nurse knows that maturation can be a threat to internal validity of the research study. Which is an example of maturation? A) A heat wave occurred during the study and clients who normally exercised outside were unable to do so. B) A client developed fatigue and was unable to complete the exercise program. C) Repeated stress tests on stationary bicycles demotivated clients from participating. D) Inclusion of a former Olympic athlete in the study skewed the results.

Ans: B Feedback: Maturation is unplanned and unrecognized changes in the participants that could affect the findings of the study, such as fatigue, hunger, or increased knowledge. History is events that are occurring during the study, which could influence participants' responses to the intervention. Testing is effect of multiple measurements of participants' responses that could influence the participants' responses, thereby altering the outcome of the study. Selection is the process by which participants are selected and grouped for a study. This threat is more likely to occur when randomization is not possible.

A client arrives at the clinic reporting diarrhea and flu-like symptoms. On questioning, the client tells the nurse about a family gathering she attended recently where she had some smoked seafood. Which foodborne illness should the nurse most suspect in this client? A) Campylobacter B) Listeria monocytogenes C) Salmonella D) Escherichia coli O157:H7

Ans: B Feedback: Nurses and other healthcare providers should suspect listeriosis in high-risk clients with a recent history of eating delicatessen food, soft cheeses, or smoked seafood who become ill with diarrhea and/or flu-like symptoms. Other infectious organisms that commonly cause foodborne illnesses include noroviruses, Listeria monocytogenes, nontyphoid Salmonella, and E. coli O157:H7. Campylobacter is the most common cause of bacterial foodborne illness in the United States, and it is an important cause of diarrheal illness throughout the world regardless of people's age.

Which most accurately defines "rate"? A) Course of a disease or condition from the onset to resolution B) Primary measurement used to describe either the occurrence or the existence of a specific state of health or illness C) Probability or likelihood that a disease or illness will occur in a group of people who presently do not have the problem D) Characteristic or event that has been shown to increase the probability that a specific disease or illness will develop

Ans: B Feedback: Rate is the primary measurement used to describe either the occurrence or the existence of a specific state of health or illness. Natural history is the course of a disease or condition from the onset to resolution. Risk is the probability or likelihood that a disease or illness will occur in a group of people who presently do not have the problem. A risk factor is a characteristic or event that has been shown to increase the probability that a specific disease or illness will develop.

Which correctly defines sensitivity? A) The ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group B) Ability of a test to correctly identify people who have a health problem or the probability of testing positive if the health problem is truly present C) Variations measured in hours, days, weeks, or months and commonly used to quantify outbreaks of infectious disease D) Ability of a test to correctly identify people who do not have a health problem or the probability of testing negative if the health problem is truly absent

Ans: B Feedback: Sensitivity is the ability of a test to correctly identify people who have a health problem or the probability of testing positive if the health problem is truly present. Relative risk ratio is the ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group. Short-term changes are variations measured in hours, days, weeks, or months and are commonly used to quantify outbreaks of infectious disease. Specificity is the ability of a test to correctly identify people who do not have a health problem or the probability of testing negative if the health problem is truly absent.

The community health nurse works in a region where severe acute respiratory syndrome (SARS) has just been reintroduced into the environment. Which measure is imperative for the nurse to take to prevent spread of the disease? A) Prophylactic antibiotics B) Enhanced infection control measures C) Use of alcohol cleansers D) Report of clusters to the Centers for Disease Control and Prevention

Ans: B Feedback: The main lessons learned from SARS, the first new infectious disease to emerge in the 21st century, were that (1) astute healthcare providers are likely to be the key to early detection and reporting of initial cases of SARS-coronavirus disease, (2) containment of disease requires the diligent application of enhanced infection control measures at the national and local levels, the same measures that will defeat SARS should it reemerge, and (3) control of an emerging infection necessitates swift action by healthcare providers as well as an adequate public health infrastructure. Prophylactic antibiotics would not be effective against a virus. Use of alcohol cleansers would not be as effective as full, enhanced infection control measures. Reporting clusters to the Centers for Disease Control and Prevention can help in the early detection of the disease, but in and of itself will not help contain it.

Which ensures that a study's results are not due to chance alone? A) Rejecting the null hypothesis B) Setting the p value to .05 C) Calculating the risk ratio D) Using a preventive study design

Ans: B Feedback: The researcher should set the expected statistical p value, generally at .05, to ensure that the study results are not due to chance alone. Rejecting the null hypothesis when it is true is known as a type I error and does not ensure that a study's results are not due to chance alone. Relative risk is a ratio ranging from 0 to infinity that indicates the strength of the association between the risk factor and the outcome. However, calculating it does not ensure that a study's results are not due to chance alone. Using a preventive study design does not ensure that a study's results are not due to chance alone.

Which represents the correct order of the three stages of the natural history of disease? A) Pathological onset, manifestation of clinical disease, presymptomatic B) Presymptomatic, pathological onset, manifestation of clinical disease C) Pathological onset, presymptomatic, manifestation of clinical disease D) Manifestation of clinical disease, presymptomatic, pathological onset

Ans: C Feedback: Epidemiologic research has established the natural history of most illnesses. This refers to the course of a disease or condition from the onset to resolution. It includes (1) the pathological onset stage, (2) the presymptomatic stage, and (3) the manifestation of clinical disease.

In researching an outbreak of malaria in the developing nation where the nurse currently works, the nurse decides to not focus on the role of mosquitoes in transmitting the disease but on how the physical environment of the community, biological aspects of the community, and social customs interact to affect the prevalence of this disease. Which epidemiological model is the nurse using? A) Epidemiologic triad B) Wheel of causation C) Web of causation D) Natural history

Ans: B Feedback: The wheel of causation de-emphasizes the agent as the sole cause of disease while emphasizing the interplay of physical, biological, and social environments. The epidemiologic triad is the classic model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment, not by any single factor. The web of causation is an epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness. Natural history is the course of a disease or condition from the onset to resolution.

Nursing students in an enclosed classroom begin to become ill with a gastrointestinal illness. The public health department identifies this occurrence as an emerging epidemic and isolates the population that is ill. According to microbial adaptation, those who survive the illness will then do which of the following? A) Recover with adaptive organism reintroduction into the environment B) Develop improved defenses against reinfection C) Become hosts to the organism, which is symbiotic in nature D) Become carriers of the infection, ultimately leading to an epidemi

Ans: B Feedback: Three stages of microbial adaptation and change occur over varying periods of time. During stage I, an epidemic occurs. The microbes enter a "virgin" population where hosts have no prior exposure to the organism and have few defenses. This leads to further spread in the population. Ultimately, survivors are usually left with improved defenses against reinfection. During stage II, the infection becomes endemic or continuously present in a geographic area or population of people. Routine childhood diseases are an example of such infections. During stage III, symbiosis is possible. Further adaptation occurs, resulting in mutual tolerance and sometimes mutual benefit for both the microorganism and the host. This is the preferred outcome.

A student nurse asks if an infectious disease is the same thing as a communicable disease. The nurse explains that an infectious disease is not necessarily a communicable disease. Which must a communicable disease have that an infectious disease does not have to have? (Select all that apply.) A) Pathogenic microorganism B) Portal of exit from the infected person C) Means of transmission D) Portal of entry to a susceptible host E) Organism that harbors the infectious agent

Ans: B, C, D Feedback: An infectious disease in a human host is one caused by the growth of pathogenic microorganisms in the body. For a disease to be communicable, or contagious, there must be a portal of exit from the infected person (or animal), a means of transmission, and a portal of entry to a susceptible host. Thus, an infectious disease need not be contagious, or communicable.

The nurse reads a research article that reviews causality. Using knowledge of research designs, which types of design examine causality? (Select all that apply.) A) Retrospective B) Quasi-experimental C) Experimental D) Randomized, control group E) Case-controlled

Ans: B, C, D Feedback: Quasi-experimental and experimental designs are used to examine causality. The "gold standard" for research design is the randomized, control group design, which is a type of experimental design. Retrospective, or case-controlled, studies do not examine causality.

There is an outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in the community. The nurse is responsible for the dissemination of the education plan adopted by the public health department. Key components of the plan should include: (Select all that apply.) A) Quarantining infected families in their homes B) Respiratory hygiene C) Hand hygiene D) Droplet precautions for visitors in contact with affected clients E) Contact precautions for all cases

Ans: B, C, D Feedback: To prevent the transmission of all respiratory infections, respiratory hygiene/cough etiquette measures should be implemented at the first point of contact with a potentially infected person and should be incorporated into standard precautions. This includes covering the nose and mouth when coughing or sneezing, using tissues to contain respiratory secretions and disposing of them in the nearest waste receptacle after use, and hand hygiene (e.g., handwashing with nonantimicrobial soap and water, an alcohol-based hand rub, or an antiseptic hand wash) after having contact with respiratory secretions and contaminated objects/materials. In addition to standard precautions, all individuals, including visitors and healthcare providers, in contact with clients with an acute respiratory infection should use droplet precautions, which include wearing a surgical mask when in close contact (i.e., within approximately 3 feet) and on entering the room of the client. The 2013 World Health Organization guidelines for a suspected or confirmed case of MERS-CoV infection called for placing the client in a single isolation room with equal or greater than 12 air exchanges per hour, not quarantining infected families in their homes. Contact precautions are only needed when contact with blood, body fluids, secretions, or nonintact skin is anticipated.

Ten documented cases of West Nile virus (WNV) have occurred recently in the community. To reduce the transmission of the virus, the nurse should educate the members of the community to: (Select all that apply.) A) Avoid contact with birds B) Avoid contact with mosquitoes C) Avoid those with a confirmed diagnosis D) Eliminate standing water E) Avoid exposure to the environment during the daylight hours

Ans: B, D Feedback: WNV virus is not transmitted from person to person but from mosquito to person. No isolation precautions are indicated other than standard precautions. The Centers for Disease Control and Prevention (CDC) guidelines emphasize avian, animal, mosquito, and human WNV surveillance, along with control and elimination of mosquito breeding sites such as standing water in flowerpots, buckets, and old tires. The CDC recommends using an insect repellent such as DEET (N, N-diethyl-m-toluamide) or picaridin when outdoors, following the directions on the package. Because mosquitoes are most active at dusk and dawn, in addition to an insect repellent, people should wear long sleeves and pants when outdoors during these hours. Screens on windows and doors will keep mosquitoes out.

The nurse is participating in study that considers the effect that use of netting around beds has on the incidence of malaria in a community of subjects in Africa. Which type of study would be best for this purpose? A) Cohort B) Case-control C) Preventive D) Therapeutic

Ans: C Feedback: A preventive study is focused on the effect of measures to prevent the occurrence of disease in subjects. Cohort studies, sometimes referred to as longitudinal studies, are prospective studies that monitor subjects over time to find associations between risk factors and health outcomes. In their simplest form, a sample (cohort) of subjects who are exposed to the risk factor(s) is matched with a sample of subjects not exposed to the risk factor. Cohort studies attempt to find cause-and-effect relationships. Case-control studies, also known as retrospective studies, work backward from the effect to the suspected cause. Subjects are selected on the basis of the presence or absence of the disease or outcome in question: one group of people (case-subjects) with the health problem and another group without the health problem (controls). The two groups are then compared to determine the presence of specific exposures or risk factors. Therapeutic trials are based on secondary prevention, which focuses on limiting the spread of disease, and where the treatment (independent variable) is manipulated by the researcher.

Person, place, and time characterize the description of an epidemiologic problem. Using knowledge of outbreak investigations, which occurs with propagated outbreaks? A) Same person or vehicle as the reservoir or means of transmission B) Infection transmitted from person to person over a short period of time C) Generating secondary infections with intervals between peaks that approximate the usual incubation period for the infection D) Generating tertiary infections following exposure to a primary case

Ans: C Feedback: A propagated outbreak is one where the infection is transmitted from person to person over a longer period of time than with a common source outbreak, and it can generate secondary infections with intervals between peaks that approximate the usual incubation period for the infection. A common source outbreak is one that has the same origin. Secondary infections are those that occur within the accepted incubation period following exposure to a primary case.

The nurse reviews published research studies on the number of heart clients who are actively involved in exercise programs following a heart attack in preparation of conducting similar research. Using knowledge of research validity, which threat to external validity must be considered? A) Loss of a subject due to a second heart attack B) Selection of a subject who does not meet the eligibility criteria for the study C) A subject pedaling faster on the stationary bicycle whenever an examiner walks in the room D) An unexpected increase in a subject's appetite that could affect the study

Ans: C Feedback: A threat to external validity is reactivity, also known as the "Hawthorne effect," which occurs when participants behave in a certain way because they know they are being studied, affecting the generalizability of the findings. Threats to internal validity include mortality (the loss of subjects from the study), selection (the process by which participants are selected and grouped for a study), and maturation (the unplanned and unrecognized changes in the participants that could affect the findings of the study, such as fatigue, hunger, or increased knowledge).

The best description of a type II error is that it occurs when: A) The null hypothesis is rejected when it is true. B) One rejects the alternative hypothesis when it is false. C) The null hypothesis is accepted when it is false. D) One accepts the alternative hypothesis when it is true.

Ans: C Feedback: A type II error occurs when one accepts the null hypothesis when it is false. A type I error occurs when the null hypothesis is rejected when it is true.

The nurse assesses a client in the local neighborhood clinic. He exhibits signs and symptoms of tuberculosis (TB) yet has a negative tuberculin skin test result. The nurse suspects that the physician may further test the client because he: A) Visited Central America recently B) Is recovering from jet lag C) Is HIV positive D) Works in a factory setting

Ans: C Feedback: Active TB infection is characterized by a chronic productive cough, low-grade fever, night sweats, and weight loss, along with a positive purified protein derivative (PPD) tuberculin skin test result. People with active TB are contagious. However, certain people who are anergic (lack an immune response to an antigen) may not have a positive PPD (e.g., persons with HIV). Having visited Central America recently, recovering from jet lag, and working in a factory setting would not produce a false negative result on the tuberculin skin test.

A man who lives in a homeless shelter is diagnosed with active tuberculosis (TB). The shelter keeps a list of those who are assigned beds, and the majority of those sleeping there are regulars. Which finding would indicate a positive tuberculin skin test result using a two-step process? A) 4-mm induration B) 2-mm induration C) 6-mm induration D) 3-mm induration

Ans: C Feedback: All high- and medium-priority contacts who do not have a documented previous positive tuberculin skin test result or previous TB disease should receive a baseline purified protein derivative (PPD) tuberculin skin test. The reaction to the intracutaneously injected PPD tuberculin skin test is the classic example of a delayed (cellular) hypersensitivity reaction, which induces induration. Induration of ≥ 5 mm is considered a positive result in people who have an initial induration of 0 mm.

City A has a population of people who are exposed to HIV, whereas City B has a population of people who are considered nonexposed to HIV. There were 3,267 new HIV cases in a given year for City A, with a population (exposed) of 10,000,000. There were only 5 new HIV cases in the same year for City B, with a population (nonexposed) of 150,000. Which is the attributable risk of HIV occurring in City A in terms of cases per 100,000 population? A) 3.33 B) 13.55 C) 29.34 D) 32.67

Ans: C Feedback: Attributable risk is calculated by subtracting the incidence rate in a nonexposed population from the incidence rate in an exposed population. In this case, we first need to calculate the individual incidence rates for City A and City B and then subtract to find the attributable risk for City A. The incidence rate for City A is calculated as follows: 3,267/10,000,000 = 0.0003267 × 100,000 = 32.67 cases per 100,000 population. The incidence rate for City B is calculated as follows: 5/150,000 = 0.0000333 × 100,000 = 3.33 cases per 100,000 population. The attributable risk for HIV occurring in City A, then, is calculated as follows: 32.67 - 3.33 = 29.34 cases per 100,000 population.

The community health nurse knows that early attempts to understand illness and disease focused on the study of the experiences of individual people. Using this knowledge, how would the nurse define epidemiology to a group of nursing students? A) An outbreak that occurs when there is an increased incidence of a disease beyond that which is normally found in the population B) Model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment C) Study of the distribution and determinants of states of health and illness in human populations D) Epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness

Ans: C Feedback: Epidemiology is the study of the distribution and determinants of states of health and illness in human populations. An epidemic is an outbreak that occurs when there is an increased incidence of a disease beyond that which is normally found in the population. The epidemiologic triad is a model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment. The web of causation is an epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness.

A client reports symptoms of severe abdominal cramps, bloody diarrhea, and vomiting after eating commercially packaged salad. The nurse suspects Escherichia coli O157:H7. The client asks about the average time of resolution of these symptoms. What time frame should the nurse provide? A) 3 to 5 days B) 5 to 7 days C) 7 to 10 days D) 12 to 14 days

Ans: C Feedback: Escherichia coli O157:H7, a deadly toxin-producing bacterium, produces symptoms of severe abdominal cramps, bloody and nonbloody diarrhea, and vomiting that generally resolve within 7 to 10 days.

Who used statistics to improve public health in England? A) William Farr B) John Graunt C) Florence Nightingale D) John Snow

Ans: C Feedback: Florence Nightingale used statistics to improve public health in England. William Farr is considered the father of modern statistics. John Graunt analyzed weekly reports of births and deaths. John Snow performed epidemiologic research on transmission of cholera using natural experiments, mapping, and rates.

An 80-year-old client is being treated for chronic urinary tract infections. She has received multiple antibiotics in the past 6 months. The physician orders a urine culture. The results of the urine culture are as follows: Staphylococcus aureus >100,000 colonies and demonstrated resistance to sulfamethoxazole and trimethoprim (Bactrim), penicillin, methicillin, and erythromycin. The client is diagnosed with methicillin-resistant Staphylococcus aureus (MRSA) on the basis of the findings of her urine test. Based on the client's history, a cause of the MRSA might be microbial: A) Rejection B) Assimilation C) Adaptation D) Stagnation

Ans: C Feedback: Microbial adaptation and change in response to the overuse of antibiotics and consequent accumulation in the environment will cause the rapid evolution of resistant pathogens. MRSA is not associated with microbes being rejected, assimilated, or stagnant.

Which rate measures the number of people in a given population who have influenza at a given point in time? A) Adjusted B) Incidence C) Prevalence D) Specific

Ans: C Feedback: Prevalence rate is the measure of the number of people in a given population who have an existing condition at a given point in time. Adjusted rate is the statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another. Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time. Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator. Often people are divided into subgroups by age and sex, although any characteristic can be used.

Incidence rates for groups exposed to a secondhand smoke are compared with the incidence rates for people who are not exposed to secondhand smoke. This will measure the: A) Incidence density B) Prevalence rate C) Relative risk ratio D) Specific rate

Ans: C Feedback: Relative risk ratio is the ratio of the incidence rate in the exposed group to the incidence rate in the nonexposed group. Incidence density is the use of a person-time denominator in the calculation of rates. A person-day reflects one person at risk for 1 day, and a person-year represents one person at risk for 1 year. Prevalence rate is the measure of the number of people in a given population who have an existing condition at a given point in time. Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator.

A client presents with several ulcerative sores on his penis that are firm, round, and painless. He also has rough, reddish brown spots on his palms and the bottoms of his feet. He acknowledges that he is sexually active with multiple partners and is inconsistent in his use of a condom. Which sexually transmitted infection should the nurse most suspect in this client? A) Gonorrhea B) Chlamydia C) Syphilis D) Human papillomavirus

Ans: C Feedback: Syphilis is primarily indicated by ulcerative sores occurring mainly on the external genitals, vagina, anus, or in the rectum, although they can occur on the lips or in the mouth. The sore is usually firm, round, and painless. Rashes associated with secondary syphilis appear as rough, red, or reddish brown spots both on the palms of the hands and/or the bottoms of the feet. Infections with Neisseria gonorrhoeae, like those resulting from Chlamydia trachomatis, cause several clinical syndromes including urogenital, pharyngeal, and rectal infections in males and females, and conjunctivitis in adults and neonates. Chlamydia is known as a "silent" infection because most infected people are asymptomatic and lack abnormal physical examination findings. Men who are symptomatic typically have urethritis, with a mucoid or watery urethral discharge and dysuria. A minority of infected men develop epididymitis (with or without symptomatic urethritis), presenting with unilateral testicular pain, tenderness, and swelling. Human papillomavirus infections, if manifest, are primarily indicated by genital warts.

Which most accurately describes how disease patterns have changed from 1900 to the present? A) Morbidity and mortality from infectious diseases have increased. B) Morbidity and mortality from unintentional injuries have decreased. C) Morbidity and mortality from chronic degenerative conditions have decreased. D) Morbidity and mortality from noninfectious diseases have increased.

Ans: D Feedback: Primarily as a result of improved public health practices in the early 20th century, life expectancy in the United States, the United Kingdom, and European countries, as well as in other developed countries, rose. With it, a change in the patterns of disease occurred. No longer are infectious diseases the leading causes of death; the morbidity and mortality from noninfectious diseases and chronic degenerative conditions have Increased.

The nurse is conducting a study that will consider how heart clients respond to various interventions following a heart attack. The nurse is concerned about the threat that testing could pose to the internal validity of the study. How might testing affect the study? A) The long commute that a subject must take to a testing center as part of the study might change the subject's response to an intervention. B) One subject develops an unrelated anemia, which causes fatigue, which in turn affects the outcome of the study. C) Multiple measurements of participants' cortisol levels could cause stress in the participants and thus influence their cortisol levels, thereby altering the outcome of the study. D) Mistakes are made when a number of subjects who should have been assigned to one intervention group are assigned to another, which may affect the outcome of the study.

Ans: C Feedback: Testing is the effect of multiple measurements of participants' responses that could influence the participants' responses, thereby altering the outcome of the study. History is events that are occurring during the study, which could influence participants' responses to the intervention. Maturation is unplanned and unrecognized changes in the participants that could affect the findings of the study, such as fatigue, hunger, or increased knowledge. Selection is the process by which participants are selected and grouped for a study. This threat is more likely to occur when randomization is not possible.

The nurse works with a female client who recently developed an infection of Staphylococcus aureus while in the hospital. In this case, S. aureus is which component in the chain of infection? A) Host B) Environmental reservoir C) Agent D) Portal

Ans: C Feedback: The agent, or the microbe that causes the disease, is the "what" of the epidemiologic triangle. The host, or the organism that is harboring the infectious agent, is the "who" of the triangle. The environment, which includes those external factors that cause or allow disease transmission, is the "where" of the triangle. Other necessary elements include a portal of exit from the host, environmental reservoirs, transmission, and a portal of entry to a new host.

The nurse wishes to conduct a study on the effectiveness of animal-assisted therapy in alleviating symptoms of depression. One group of subjects would attend regular counseling sessions in the company of a dog, whereas the other group would attend regular counseling sessions without a dog present. In this study, the dogs would represent: A) Control group B) Treatment group C) Intervention D) Placebo

Ans: C Feedback: The hallmark of the experimental study is random assignment of subjects to treatment (intervention) and control groups, which controls for potential unknown confounding variables. In this case, the dogs are the intervention or treatment, the group of subjects who are exposed to them during counseling sessions are the treatment group, and the group of subjects who are not exposed to them are the control group. Placebo refers to the control group.

When an infectious agent enters the host and begins to multiply, an infection occurs. The time between exposure to an infectious agent and the manifestation of symptoms in the host is known as: A) Carrier time B) Colonization C) Incubation period D) Latent period

Ans: C Feedback: The time between exposure to an infectious agent and the manifestation of symptoms in the host is called the incubation period. Asymptomatic people are carriers of a virus and can transmit the virus to others through percutaneous inoculation, exposure to mucous membranes, and sexual contact. When an infectious agent is present and there are no clinical signs of disease, colonization with the infectious agent is said to have occurred, and the infected person is capable of transmitting the agent. The latent period is the stage of a disease during which symptoms are hidden.

The nurse explores all of the possible factors that contribute to coronary artery disease in the community as links in multiple interrelated chains. Which epidemiologic models is the nurse using? A) Epidemiologic triad B) Wheel of causation C) Web of causation D) Natural history

Ans: C Feedback: The web of causation is an epidemiologic model that strongly emphasizes the concept of multiple causation while de-emphasizing the role of agents in explaining illness. The epidemiologic triad is the classic model based on the belief that health status is determined by the interaction of the characteristics of the host, agent, and environment, not by any single factor. The wheel of causation de-emphasizes the agent as the sole cause of disease while emphasizing the interplay of physical, biological, and social environments. Natural history is the course of a disease or condition from the onset to resolution.

Clients in the nurse's caseload have been requested to participate in a therapeutic trial about H1N1 influenza. Using knowledge of trials, the nurse tells the clients that the trial: A) Is based on primary prevention of H1N1 influenza B) Is dependent variable manipulated by the researcher C) Focuses on limiting the spread of H1N1 influenza D) Focuses on reducing the incidence of H1N1 influenza

Ans: C Feedback: Therapeutic trials are based on secondary prevention, which focuses on limiting the spread of disease and where the treatment (independent variable) is manipulated by the researcher. Preventive trials focus on primary prevention to reduce the incidence of disease.

Which criteria must be met to define a water-associated disease outbreak? A) Two or more people with laboratory-confirmed primary amebic meningoencephalitis B) Two or more cases of chemical poisoning if water quality data indicate contamination by the chemical C) Two or more people having experienced a similar illness after exposure to water D) Epidemiologic evidence implicating drinking water as the probable source of the illness

Ans: C Feedback: Two criteria must be met for an event to be defined as a water-associated disease outbreak. First, two or more people must have experienced a similar illness after exposure to water. Second, epidemiologic evidence must implicate recreational water (not drinking water) or volatilization of water-associated compounds into the air surrounding the water as the probable source of illness. Evidence of primary amebic meningoencephalitis and chemical poisoning are not required for confirmation of a water-associated disease outbreak.

A 16-year-old client visits the community health clinic with concerns that she may have a sexually transmitted infection (STI). She asks whether STIs are treatable. STIs that are easily treated and curable include: (Select all that apply.) A) Human papillomavirus B) Herpes simplex C) Chlamydia D) Gonorrhea E) Syphilis

Ans: C, D, E Feedback: Infections caused by bacteria can be treated and usually cured with antibiotics, but those caused by viruses cannot be cured this way. Chlamydia, gonorrhea, syphilis—all bacterial—and trichomoniasis—parasitic are easily treated with antibiotics and cured if diagnosed early. Human papillomavirus and herpes simplex are viral infections that are not treatable.

. Which best describes a risk factor? A) Course of a disease or condition from the onset to resolution B) Primary measurement used to describe either the occurrence or the existence of a specific state of health or illness C) Probability or likelihood that a disease or illness will occur in a group of people who presently do not have the problem D) Characteristic or event that has been shown to increase the probability that a specific disease or illness will develop

Ans: D Feedback: A risk factor is a characteristic or event that has been shown to increase the probability that a specific disease or illness will develop. An outbreak is a course of a disease or condition from the onset to resolution. Rate is a primary measurement used to describe either the occurrence or the existence of a specific state of health or illness. Risk is the probability or likelihood that a disease or illness will occur in a group of people who presently do not have the problem.

The nurse is conducting a study on heart clients who are actively involved in exercise programs following a heart attack. The nurse should consider which as a threat to internal validity? A) Some subjects run faster on the treadmill when a researcher walks through the room. B) Including an exciting new cross-fit training program as one of the exercise options that can accommodate a few of the study subjects C) Your fervent belief from personal experience that intense cardiovascular exercise can speed recovery and prevent further heart attacks D) Using a variety of stationary bicycles for stress testing

Ans: D Feedback: A threat to internal validity is instrumentation, which refers to changes in the measurement instrument used in the study and which results in inconsistent data collection. Threats to external validity include reactivity, novelty, and experimenter/participant effect.

The nurse is preparing to do a research study on the effects of tight insulin control for diabetes. Using the knowledge that epidemiologic research can be descriptive or analytical, which would be the strongest study design to consider? A) Retrospective B) Quasi-experimental C) Experimental D) Randomized, control group

Ans: D Feedback: Analytical research study designs are on a continuum, ranging from strongest to weakest designs. The research continuum indicates that experimental study designs are the strongest because they control for all factors except that which is under study, with the "gold standard" for research design being the randomized, control group design. Two analytical designs, the prospective correlational design and the retrospective correlational design, are "weaker" designs on the continuum. Quasi-experimental study designs are stronger than retrospective studies but weaker than experimental because assignment of subjects into groups is not randomized or the researcher is unable to manipulate the variable under study.

You have heard rumors in the hospital where you work of an Ebola outbreak in your community and you would like to investigate it further. Which of the following should be your first step in the investigation? A) Identify the names of the people infected by the virus B) Formulate and test hypotheses as to the most probable causative factors C) Implement a plan for control of the outbreak D) Establish the existence of the outbreak

Ans: D Feedback: Because you have only heard rumors, you should first establish the existence of the outbreak before identifying those infected, formulating and testing hypotheses, and implementing a plan for control of the outbreak.

Which occurs in the epidemiologic process that is similar to the diagnosis phase of the nursing process? A) Data are gathered from reliable sources B) Healthcare needs and assets are identified C) Goals and objectives for care are established D) A tentative hypothesis is formulated

Ans: D Feedback: During the diagnosis phase of the epidemiologic process, a tentative hypothesis is formulated. During the assessment phase of the epidemiologic process, data are gathered from reliable sources. During the diagnosis phase of the nursing process, healthcare needs and assets are identified and goals and objectives for care are established

The client is diagnosed with Lyme disease. He states that he is not a hiker and does not remember being bitten by a tick. As part of the education plan, the nurse should state: A) "You must have been bitten by a tick and didn't recognize it as such." B) "Did you spend time in a brushy or grassy area in the last 90 days?" C) "Conduct a full-body tick check once a week during the summer." D) "A history of a tick bite is not required."

Ans: D Feedback: Exposure to Lyme disease is defined as having spent time (less than or equal to 30 days before onset of the initial skin lesion) in wooded, brushy, or grassy areas (i.e., potential tick habitats) in a county in which Lyme disease is endemic. A history of tick bite is not required. A county in which the disease is endemic is one in which at least two confirmed cases have been previously acquired or in which established populations of a known tick vector are infected with Borrelia burgdorferi. Those who are outdoors should do a final, full-body tick check at the end of the day (not once a week) for adults, children, and pets.

Four employees at a local restaurant have positive purified protein derivative (PPD) tuberculin skin tests and have been diagnosed with latent tuberculosis (TB) infection. Which employee would be at the greatest risk for contracting active TB disease? A) Works two jobs B) Vacations in South America C) Cooks the food D) Takes immunosuppressants

Ans: D Feedback: In many people who have latent TB infection, the Mycobacterium tuberculosis bacteria remain inactive for a lifetime without causing active TB disease. But in other people, especially those who have weak immune systems, the bacteria become active and cause TB disease. Working two jobs, vacationing in South America, and cooking food would not put one with a latent TB infection at greater risk for contracting active TB disease.

The student-nurse discusses transmission that involves contact of a susceptible host with a vehicle. Based on the chain of infection links, which exemplifies a vehicle? A) Animals B) Insects C) Reptiles D) Water

Ans: D Feedback: Indirect contact involves contact of a susceptible host with a contaminated intermediate inanimate object, called a vehicle, such as a contaminated surgical instrument, needle, toy, soiled clothing, or bed linen. Vehicles also include food, water, and contaminated hands that are not washed. Indirect contact also includes vector transmission. Vectors are animal or insect carriers of infectious agents.

Who was the best known epidemiologist of the 19th century and used population data and personal observations to investigate the epidemic of cholera that occurred from 1848 through 1854? A) William Farr B) John Graunt C) Florence Nightingale D) John Snow

Ans: D Feedback: John Snow performed epidemiologic research on transmission of cholera using natural experiments, mapping, and rates. William Farr is considered the father of modern statistics. John Graunt analyzed weekly reports of births and deaths. Florence Nightingale used statistics to improve public health in England.

The community health nurse addresses an outbreak of viral spinal meningitis in the community. Referring to Leavell and Clark's natural history of disease model, which example of tertiary prevention might the nurse consider in this situation? A) Initiate vaccinations for all people who have not yet been infected. B) Familiarize yourself with the signs and symptoms of the disease so that you can provide early diagnosis and treatment of it. C) Encourage any who think they might have symptoms of the disease to come to the community health clinic to be assessed as soon as possible, to prevent associated disabilities. D) Refer clients who have experienced neurological deficits because of the disease to a neurologist to begin rehabilitation.

Ans: D Feedback: Primary prevention measures specific to the disease can be implemented at this stage to prevent the onset in a population of well people. The period of pathogenesis begins when there are biological, psychological, or other responses within the host. Secondary prevention measures that focus on early diagnosis and prompt treatment, limiting resulting disabilities, are implemented during the early stages of the disease. Tertiary prevention follows with rehabilitation measures that enable the individual to function at his or her maximum capability.

The nurse admits a client to the hospital with the diagnosis of Escherichia coli O157:H7. The client is dehydrated and febrile. During the history phase of the admission, the client states that he doesn't know how he could have gotten sick at the local county fair—the hamburger he bought was well done. Upon further discussion, the nurse suspects the transmission may have occurred because of: A) Use of a gas barbecue B) Improper cleaning of the cooking tools C) Use of wood instead of charcoal to cook the meat D) Animals roaming in the fair grounds

Ans: D Feedback: Recent cases of hemolytic-uremic syndrome (HUS) have been associated with outbreaks of E. coli O157:H7 infections, which were apparently caused by contact with animals in public settings, including fairs, farm tours, and petting zoos. Experience from these and previous outbreaks underscores the necessity for adequate control measures to reduce zoonotic transmission. The Centers for Disease Control and Prevention has developed standardized recommendations for public health officials, veterinarians, animal exhibitors, and visitors to animal exhibits; it established that hand washing is the single most important prevention step for reducing the risk for disease transmission. Other critical recommendations for venues with animals are the inclusion of transition areas between animal and nonanimal areas (e.g., where food is sold) and proper care and management of animals in public settings. Use of a gas barbecue, use of wood instead of charcoal to cook meat, and improperly cleaned cooking tools are not associated with E. coli infection.

The nurse is conducting research on the relative risk of acquiring lung cancer as a result of being exposed to secondhand smoke. The nurse is studying two different groups. Group A includes 400 adults who do not smoke but are exposed to secondhand smoke in their home on a daily basis. Group B includes 400 adults who do not smoke and are not exposed to secondhand smoke in their home. Over the course of 10 years, 20 subjects in Group A are diagnosed with lung cancer, whereas only 2 subjects in Group B are diagnosed with lung cancer. Which is the relative risk ratio that would result from this study? A) 0.5 B) 1 C) 5 D) 10

Ans: D Feedback: Relative risk ratio compares the incidence rate of a group exposed to a certain risk factor with the incidence rate of a group not exposed to the risk factor. It is calculated by dividing the incidence rate in the exposed group by the incidence rate in the nonexposed group. In this case, we need to first calculate the separate incidence rates for Group A and Group B and then divide to find the relative risk ratio. The incidence rate for Group A is calculated as follows: 20/400 = 0.05 × 1,000 = 50 cases per 1,000 population. The incidence rate for Group B is calculated as follows: 2/400 = 0.005 × 1,000 = 5 cases per 1,000 population. The relative risk ratio, then, is calculated as follows: 50/5 = 10.

The nurse wishes to compare the number of persons aged 40 to 49 years who die each year with the midyear population of persons in this age range, per 100,000 population. Which type of rate is the nurse attempting to calculate? A) Adjusted B) Incidence C) Prevalence D) Specific

Ans: D Feedback: Specific rates are detailed rates that are calculated using the number of people in the smaller subgroups of the population in the denominator. Often people are divided into subgroups by age and sex, although any characteristic can be used. Adjusted rate is the statistical procedure that removes the effects of differences in the composition of a population, such as age, when comparing one with another. Incidence rate is the measure of the probability that people without a certain condition will develop that condition over a period of time. Prevalence rate is the measure of the number of people in a given population who have an existing condition at a given point in time.

Which agency has an electronic surveillance system for the early notification of community-based epidemics? A) Department of Health and Human Services B) Centers for Disease Control and Prevention C) World Health Organization D) Department of Defense

Ans: D Feedback: The Department of Defense (DoD) has an electronic surveillance system for the early notification of community-based epidemics (ESSENCE), which has been in operation since 2001 to detect infectious disease outbreaks. At the federal level, the Department of Health and Human Services (DHHS) is the U.S. public health infrastructure that develops policies to protect the nation's health. The Centers for Disease Control and Prevention (CDC) is a major DHHS agency that protects the nation's health by developing guidelines that promote health and quality of life by preventing and controlling disease, injury, and disability. The CDC is also a partner with the World Health Organization (WHO) through the Global Outbreak Alert and Response Network and the WHO Surveillance and Response system, which provide international epidemic alerts and responses.

International health experts indicate that the avian flu is the virus most likely to cause the next pandemic. What may improve its transmissibility to the public? A) Increase in consumption of chicken B) Increase in autoimmune disease incidence C) Shift to zoonotic transmission D) Antigenic shift

Ans: D Feedback: The H5N1 virus can improve its transmissibility among humans by two mechanisms. The first is antigenic shift, a "reassortment" event, in which genetic material is exchanged between human and avian viruses during coinfection of a human or an animal such as a pig. Reassortment could result in a fully transmissible pandemic virus, which could rapidly spread throughout the world. The second mechanism is a more gradual process of antigenic drift, an adaptive mutation, whereby the capability of the virus to bind to human cells increases during subsequent infections of humans. Nearly all of the human infections with H5N1, which are the largest documented since its emergence in humans in 1997, were a result of people having direct or close contact with infected poultry or contaminated surfaces, but not a result of consuming chicken. An increase in incidence of autoimmune diseases, which involve one's own immune system attacking the body, is not related to the spread of avian influenza and would not lead to a pandemic. The avian flu is already transmitted primarily in a zoonotic manner, so any shift in transmission would be to human-to-human transmission, which would be more likely to cause a pandemic than zoonotic transmission.

Each employee in a small community hospital is informed that he or she needs a tuberculin skin test and of the date that the test is due. The kitchen employees tell the nurse that they don't need the test and never had to have it before. The nurse should respond with: A) The test does not need to be given if you do not have client contact. B) Tuberculosis guidelines require testing of an entire healthcare setting. C) The test will not hurt; we won't fire you if you test positive. D) The tuberculosis guidelines state kitchen workers are at risk.

B Feedback: The 2005 tuberculosis (TB) infection control guidelines emphasize actions to maintain momentum and expertise needed to avert another TB resurgence and to eliminate the lingering threat to healthcare personnel, which is mainly from clients or others with unsuspected and undiagnosed infectious TB disease. A sample recommendation is that the term "tuberculin skin tests" be used rather than purified protein derivative. The scope of settings in which the guidelines apply has been broadened to include laboratories and additional outclient and nontraditional healthcare settings. These recommendations also apply to an entire healthcare setting rather than to areas within a setting.

The nurse researches the relationship between frequent ingestion of fast foods and obesity. The nurse finds that in a population that eats at least five fast food meals per week on average, the incidence rate of people who are obese is 735/1,000 population. In the population that eats only one fast food meal per week on average, the incidence rate of people who are obese is 245/1,000 population. Based on these findings, what is the relative risk of developing obesity in those who eat at least five fast food meals per week? A) 0.3 B) 0.7 C) 1 D) 3

D Feedback: Relative risk (RR) is defined as the ratio of disease incidence (or death) in an exposed population to that in an unexposed population. The assumption is that the underlying risk without the exposure is the same in both groups. Relative risk is a ratio ranging from 0 to infinity that indicates the strength of the association between the risk factor and the outcome. It is calculated by dividing the risk in the group exposed to a risk factor by the risk in the unexposed group. In this case, we perform the following calculation: 735/245 = 3. An RR significantly greater than 1 (statistically) indicates that the exposure is associated with increased risk of disease. An RR significantly less than 1 (statistically) indicates that the exposure is associated with decreased risk of disease; that is, the exposure is protective. An RR not significantly different from 1 (statistically) indicates that there is no association between the exposure and the risk of disease.

The nurse studies the association of lead poisoning with residence in a home that was built before 1970. Which needs to be established to show an association between these two variables? A) A statistical relationship between lead poisoning and residence in a home built before 1970 B) That the presence or absence of residence in a home built before 1970 determines the presence or absence, respectively, of lead poisoning C) A relative risk of 1 D) A p value > 0.1

Feedback: An association is a statistical relationship between two or more events, characteristics, or other variables. Causality is the relationship between two variables in which the presence or absence of one variable (the "cause") determines the presence or absence of the other (the "effect"). A relative risk not significantly different from 1 (statistically) indicates that there is no association between the exposure and the risk of disease. A p value > 0.1 indicates a lack of statistical relationship.