chapter 1-7 questions Flashcards
- Epidemiology is broadly defines as the study of factors that influence the health of populations. The application of epidemiologic findings to decisions in the care of individual patients is:
a. Generally inappropriate
b. Known as clinical epidemiology
c. Limited to chronic disease epidemiology
d. Limited to infectious disease epidemiology
e. Limited to biologic mechanisms rather than social and environmental considerations
b
Tim has a severe heart attack at age 58. The near-death experience so scares Tim that he quits smoking. Tim’s wife is also scared into quitting smoking even though she feels fine. Tim’s son resolves never to start smoking, seeing what cigarettes have done to his dad. The act of not smoking for Tim, Tim’s wife, and Tim’s son represent:
a. Host, vector, and agent effects, respectively
b. Herd immunity
c. Tertiary prevention for Tim’s son
d. Tertiary prevention, primary prevention, and secondary prevention, respectively
e. Tertiary prevention, secondary prevention, and primary prevention, respectively
e
i. Tertiary prevention – prevents further progression of disease based on appearance of symptoms
ii. Secondary prevention – stop risk factor behavior to prevent progression of asymptomatic disease
iii. Primary prevention – earliest possible prevention – not smoking in the first place
Before quitting smoking, Tim, his cigarettes, and his tobacco smoke represent:
a. Agent, host, and environment, respectively
b. Agent, environment, and vector, respectively
c. Vector, agent, and vehicle, respectively
d. Host, vehicle, and agent, respectively
e. Vehicle, vector and agent respectively
D
i. A vehicle is an inanimate carrier of an agent of harm
ii. A host is a susceptible individual
iii. A vector and an unaffected carrier
iv. An agent is the medium of harm
For an infectious disease to occur, there must be interactions between:
a. Behavioral factors and genetic factors
b. The agent and the vector
c. The host and the agent
d. The vector and the environment
e. The vector and the host
c
i. Also requires the environment for them to come together
ii. A vector may or may not be involved
An example of the iceberg phenomenon would be:
a. The primary prevention of colon cancer
b. Giving a medicine that only partially treats an illness
c. Widely publicized fatalities caused by emerging swine flu
d. Conducting field trials in northern latitudes
e. When cold temperatures favor disease outbreaks
c
The first few cases of an emerging disease are typically the worst. These patients are considered the tip of the iceberg. The less severe patients are hidden from view initially and are considered the rest of the iceberg.
Which of the following is beyond the scope of activities undertaken by epidemiologists?
a. Analyzing cost effectiveness
b. Establishing modes of disease transmission
c. Studying how to prevent disease
d. Providing data for genetic counseling
e. Rationing health care resources
e
This is a political task that epidemiologists don’t need to worry about
Herd immunity refers to:
a. Immunity acquired from vaccines developed in herd animals
b. Immunity naturally acquired within confined herds of animals or within overcrowded human populations
c. The high levels of antibody present in a population after an epidemic
d. The prevention of disease transmission to susceptible individuals through acquired immunity in others
e. The vaccination of domestic animals to prevent disease transmission to humans.
d
Attempts to eradicate a disease through widespread immunization programs may be associated with potential adverse effects. Which of the following adverse effects is correlated with the effectiveness of a vaccine?
a. The emergence of resistant strains of infectious agents to which the vaccine is targeted
b. The loss of the natural booster effect
c. The occurrence of infection in younger age groups
d. The occurrence of allergic reactions
e. The risk of disorders of the autism spectrum
b
An airline implements a new policy requiring children over 1 year of age to have their own seats and seat belts (rather than being allowed to sit in a parent’s lab). Public health advocates support the policy because the goal is to improve travel safety. Unfortunately, given the expense of an additional plane ticket, many families choose to drive rather than fly to destinations after passage of the policy. Because road travel is substantially more dangerous than air travel, the new policy actually results in a decrease in travel safety. From a public health perspective, the results of this policy are example of:
a. Antigenic shift
b. Demographic gap
c. Ecological perspective
d. Clinical epidemiology
e. Unintended consequences
e
Evaluation of which of the following potentially preventable causes of disease is most likely to raise ethical concerns?
a. Dietary intake
b. Genetic susceptibility
c. Immunization status
d. Smoking status
e. Social support networks
b
While the pork industry lobbied aggressively against dubbing the novel H1N1 influenza virus swine flu, substantial evidence supported that this wholly new genetic variant of influenza developed from confined animal feed operations associated with commercial pig farming. The novel H1N1 virus resulted from:
a. Antigenic shift
b. Antigenic drift
c. Antibody shift
d. Antibody drift
e. Antisocial rift
a
Antigenic shift - A major genetic change
Antigenic drift - Minor alteration in surface antigens resulting from mutations
Antibody shift - Not defined phenomenon
Antibody drift - Not defined phenomenon
Antisocial rift - Occurs between competing researchers vying for the title of world’s leading influenza epidemiologist.
A study involves tracking a condition that can recur in individuals over time (e.g. heartburn or dyspepsia)..Which of the following measures would allow the authors of the study to make full use of their collected data?
a. Attributable risk
b. Incidence density
c. Period prevalence
d. Point prevalence
e. Proportional hazards
b
Incidence density - Measure reported in terms of the frequency (density) of a condition per person-time. (person-days, person-months, etc)
During a given year, 12 cases of disease X are detected in a population of 70,000 college students when those 12 students present for medical attention. Many more students have mild symptoms of the disease and do not seek care. Of the 12 detected cases, 7 result in death. The ratio of 7/12 represents:
a. The case fatality ratio
b. The crude death rate
c. The pathogenicity
d. The standardized mortality ratio
e. 1-prevalence
a
a. The case fatality ratio
b. The crude death rate
i. # of deaths caused by the condition / mid-period population
c. The pathogenicity
i. The proportion of infected persons with clinical illness
d. The standardized mortality ratio
i. The number of observed deaths based on a reference population
e. 1-prevalence
i. Not meaningful
During a given year, 12 cases of disease X are detected in a population of 70,000 college students when those 12 students present for medical attention. Many more students have mild symptoms of the disease and do not seek care. To report the incidence rate of disease X, it would be necessary to know:
a. Nothing more than the data provided
b. The pathogenicity
c. The infectiousness of the disease
d. The duration of the clinical illness
e. The midyear population at risk
e. The midyear population at risk
i. Incidence rate = # of new cases in a specified population, during a specific period / the mid-period population at risk.
During a given year, 12 cases of disease X are detected in a population of 70,000 college students when those 12 students present for medical attention. Many more students have mild symptoms of the disease and do not seek care. To report the prevalence of disease X, it would be necessary to know:
a. The cure rate
b. The duration of illness
c. The number of cases at a given time
d. The number of losses to follow-up
e. The rate at which new cases developed
c. The number of cases at a given time
i. Prevalence = # of cases in a specified population at a particular time.
This is calculated after the two populations to be compared are “given” the same age distribution, which is applied to the observed age-specific death rates of each population.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
e. Direct standardization of death rate
i. The age-specific death rates are available for the populations to be compared
This is the number of new cases over a defined study period, divided by the mid-period population at risk.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
f
This is used if age-specific death rates are unavailable in the population whose crude death rate is to be adjusted.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
g. Indirect standardizations of death rate - Applies the death rates from a reference population to the study populations.
This is not a true rate; it is actually a proportion.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
i
prevalence rate - the prevalence rate is not a true rate, only the proportion, or percentage, of persons in a specified population with a defined condition at the time of study.
This is the observed total deaths in a population, divided by the expected deaths in that population, multiplied by 100.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
j. Standardized mortality ratio
i. Often derived from indirect standardization methods.
This is useful for studying trends in the causes of death over time.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
c
This is often used as an overall index of the health status of a country.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
h
This is a fictitious rate.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
k
This is the proportion of individuals with a given condition who die of the condition.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
b. Case fatality ratio
i. Requires knowing the number of affected individuals and the number of deaths attributable to the condition.
This is the number of live births, divided by the mid-period population.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
d. Crude birth rate
i. Technically not a valid rate because not everyone in the denominator can be said to be “at risk” for the numerator event (i.e. only women of childbearing age are at risk for bearing children).
- This provides the death rate within a defined age range.
a. Age-specific death rate
b. Case fatality ratio
c. Cause-specific death rate
d. Crude birth rate
e. Direct standardization of death rate
f. Incidence rate
g. Indirect standardizations of death rate
h. Infant mortality rate
i. Prevalence rate
j. Standardized mortality ratio
k. Standardized rate
a
Age is one of the strongest predictors of mortality. Death rate that do not reflect the experience of particular age groups are difficult to interpret. Uses the population within a particular age range as the denominator and use deaths within that group as the numerator.
An outbreak of disease should be reported to the local or state health department:
a. Only if the diagnosis is certain
b. Only if the disease is infectious
c. Only if the disease is serious.
d. Only if the outbreak involves at least 10 people
e. Always.
e
Arizona, Colorado, and New Mexico report cases of an unexplained respiratory tract illness with a high case fatality ratio. Which of the following is most reliably true regarding this event?
a. The cases represent an epidemic
b. The identification of the cases is an example of active surveillance
c. It is appropriate for the CDC to investigate the cases
d. The seemingly new cases may be an artifact of improved health department surveillance.
e. If the illnesses represent an endemic disease, the cases do not constitute an outbreak.
c
Cases of “flesh-eating” group A streptococcal disease are reported in a defined population. Which of the following types of information would be most helpful for determining whether these cases represent a disease outbreak?
a. The clinical features and methods of diagnosing the disease
b. The disease vector and reservoir
c. The exact location and timing of disease onset
d. The incubation period and pattern of disease transmission
e. The usual disease patterns and reporting practices
e
An official from the state department of public health visits outpatient clinics and emergency department to determine the number of cases of post-exposure prophylaxis for rabies. The official’s action is an example of:
a. Active surveillance
b. Case finding
c. Outbreak investigation
d. Screening
e. Secondary prevention
a
An article highlighting the long-term consequences of inadequately treated Lyme disease is published in a medical journal. After a summary of the article appears in popular newspapers and magazines, patients with vague joint pains begin insisting that their physicians test them for Lyme disease. Cases in which the test results are positive are reported as cases of Lyme borreliosis. This represents:
a. Outbreak investigation
b. An epidemic of Lyme borreliosis
c. A change in reporting that would underestimate incidence
d. A change in surveillance that would overestimate the prevalence
e. A change in screening that would underestimate the likelihood of an outbreak
d. A change in surveillance that would overestimate the prevalence
i. Whenever public attention is focused on a particular health problem, an increase in the number of reported cases of the problem is likely.
The U.S. President invites a group of legislators to a formal luncheon at the White House. Within 24 hours, 11 of the 17 diners experience abdominal pain, vomiting, and diarrhea. The President does not eat the salmon and feels fine. Of the 11 symptomatic guests, 4 have fever and 7 do not; 5 have an elevated white blood cell count and 6 do not; 6 ate shrimp bisque and 5 did not; 9 ate salmon mousse and 2 did not; and 1 goes on to have surgery for acute cholecystitis resulting from an impacted calculus (stone) in the common bile duct. Of the 11 symptomatic guests, 10 recover within 3 days; the exception is the senator who underwent surgery and recovered over a longer period. The guests at this luncheon had shared no other meals at any time recently.
That 11 of 17 diners become sick:
a. Is a coincidence until proven otherwise
b. Represents a disease outbreak
c. Is attributable to bacterial infection
d. Is not an outbreak because the usual pattern of disease is unknown
e. Should be investigated by the CDC.
b
The U.S. President invites a group of legislators to a formal luncheon at the White House. Within 24 hours, 11 of the 17 diners experience abdominal pain, vomiting, and diarrhea. The President does not eat the salmon and feels fine. Of the 11 symptomatic guests, 4 have fever and 7 do not; 5 have an elevated white blood cell count and 6 do not; 6 ate shrimp bisque and 5 did not; 9 ate salmon mousse and 2 did not; and 1 goes on to have surgery for acute cholecystitis resulting from an impacted calculus (stone) in the common bile duct. Of the 11 symptomatic guests, 10 recover within 3 days; the exception is the senator who underwent surgery and recovered over a longer period. The guests at this luncheon had shared no other meals at any time recently.
The attack rate is:
a) 4/11
b) 5/11
c) 9/11
d) 1/17
e) 11/17
e) 11/17
attack rate is the proportion of exposed persons who become ill
The U.S. President invites a group of legislators to a formal luncheon at the White House. Within 24 hours, 11 of the 17 diners experience abdominal pain, vomiting, and diarrhea. The President does not eat the salmon and feels fine. Of the 11 symptomatic guests, 4 have fever and 7 do not; 5 have an elevated white blood cell count and 6 do not; 6 ate shrimp bisque and 5 did not; 9 ate salmon mousse and 2 did not; and 1 goes on to have surgery for acute cholecystitis resulting from an impacted calculus (stone) in the common bile duct. Of the 11 symptomatic guests, 10 recover within 3 days; the exception is the senator who underwent surgery and recovered over a longer period. The guests at this luncheon had shared no other meals at any time recently.
The earliest priority in investigating the phenomenon would be to: A. Close the kitchen temporarily B. Define a case investigation. C. Perform a case-control study D. Perform stool tests E. Submit food samples to the laboratory
B) Define a case
1. Establishing a diagnosis or a case definition is the earliest priority in an outbreak investigation.
The U.S. President invites a group of legislators to a formal luncheon at the White House. Within 24 hours, 11 of the 17 diners experience abdominal pain, vomiting, and diarrhea. The President does not eat the salmon and feels fine. Of the 11 symptomatic guests, 4 have fever and 7 do not; 5 have an elevated white blood cell count and 6 do not; 6 ate shrimp bisque and 5 did not; 9 ate salmon mousse and 2 did not; and 1 goes on to have surgery for acute cholecystitis resulting from an impacted calculus (stone) in the common bile duct. Of the 11 symptomatic guests, 10 recover within 3 days; the exception is the senator who underwent surgery and recovered over a longer period. The guests at this luncheon had shared no other meals at any time recently.
The best case definition for the guests’ disease would be:
A. Abdominal pain, vomiting, and diarrhea within 24 hours of the luncheon
B. Acute viral gastroenteritis
C. Staphylococcal food poisoning
D. The onset of abdominal pain and fever after the luncheon
E. An elevated white blood cell count
A. Abdominal pain, vomiting, and diarrhea within 24 hours of the luncheon
1. The case definition is required to distinguish between cases and non-cases of the disease under investigation (i.e. distinguish who is “ill” and who is “not ill” by strict criteria.)
