Epi exam 1 Flashcards
Clinical outcome of severe WNV neurologic disease was substantially worse for elderly patients. Advanced age is best described as?
a) Risk
b) Risk factor
c) Prognostic factor
d) Natural history etiology
e) None of the above
C) Prognostic factor
A study is conducted in which the rates of subsequent malarial infections are compared in communities with and without mosquito abatement programs. This is best described as…
a) Case-control study
b) Cohort study
c) Randomized controlled clinical trial
d) Latin square design crossover trial
e) None of the above
B) Cohort Study
West Nile Virus had occurred for the first time in the U.S. the preceding year. This unusual pattern of occurrence is best described as…
a) Natural occurrence
b) Prognostic outbreak
c) Sentinel case
d) Sentinel epidemic
e) Epidemic
e) epidemic
Among Staten Island residents, 2.5 per 100,000 persons developed severe West Nile Virus neurologic disease during an epidemic. This measure is best described as…
a) Incidence rate
b) Mortality rate
c) Morbidity rate
d) Median survival rate
e) None of the above
a
A study of antiviral agents is conducted for the treatment of severe West Nile Virus neurologic disease in which treatment assignments to individual patients are made by chance. This study is a…
a) Cohort trial
b) Latin square trial
c) Case-control trial
d) Randomized controlled clinical trial
e) None of the above
d
Epidemiology is broadly defined 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
The BEINGS model is a useful paradigm for:
a) Allocating public health resources
b) Asserting the impact of herd immunity
c) Determining the role of social policy on public health
d) Establishing the importance of social contacts
e) Evaluating etiologic factors in disease.
e
The BEINGS model provides a list of factors in disease causality. Which of the following factors are explicitly included in the list?
a) Behavioral, ecologic, idiopathic, nutritional, genetic, and social factors.
b) Behavioral, environmental, immunologic, nutritional, genetic, and selective factors.
c) Behavioral, environmental, immunologic,
nutritional, genetic, and social factors.
d) Biologic, environmental, immunologic, nutritional, genetic, and synergistic factors.
e) Biologic, environmental, innate, nutritional, genetic, and synergistic factors
c
What percentage of death certificate diagnoses are thought to be potentially inaccurate?
15-20% inaccurate
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
During a given year, 12 cases of disease X are detected in a population of 70,000 college students. Many more students have mild symptoms of the disease, such as persistent daydreams about selling coconuts on a Caribbean beach. 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
During a given year, 12 cases of disease X are detected in a population of 70,000 college students. Many more students have mild symptoms of the disease, such as persistent daydreams about selling coconuts on a Caribbean beach. To report the incidence rate of disease X, it would be necessary to know:
a) Nothing more than the data provided
b) The age distribution of the population
c) The case fatality ratio
d) The duration of the clinical illness
e) The midyear population at risk.
e
During a given year, 12 cases of disease X are detected in a population of 70,000 college students. Many more students have mild symptoms of the disease, such as persistent daydreams about selling coconuts on a Caribbean beach. 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) Prevalence
a
A study involves tracking recurring migraines in individuals over a 3 year period. 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
Herd immunity refers to:
a) Genetic resistance to species-specific disease
b) Immunity naturally acquired in a population
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
For an infectious disease to occur there must be interaction 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
AZ, CO, and NM report cases of a spike in respiratory tract illnesses with a high case fatality ratio. 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 departments 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’s disease is published in a medical journal. After a summary of the article appears in popular newspapers and magazine, patients with joint pains begin insisting that their physicians test them for Lyme’s 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
Among elderly subjects who are physically fit, vigorous exercise reduces the risk of heart disease. Among elderly subject who are physically unfit, the initiation of vigorous exercise might precipitate a myocardial infarction. Fitness may be considered:
a) A positive confounder
b) A negative confounder
c) A necessary cause
d) A sufficient cause
e) An effect modifier
e
In the relationship between obesity and cardiovascular disease, what are hyperlipidemia and hyperglycemia?
a) Confounders
b) Effect modifiers
c) Intervening variables
d) Necessary causes
e) Unrelated
c
When questioned years after an illness, individuals who served as cases reported more severe subjective symptoms than did those who served as controls. This probably an example of:
a) Confounding
b) Selection bias
c) Random error
d) Recall bias
e) Late-look bias
d
What is the relationship of asbestos to asbestosis?
a) Confounder
b) Effect modifier
c) Necessary cause
d) Sufficient cause
e) Synergism
c
The basic goal of epidemiologic research is to:
a) Describe associations between exposures and outcomes.
b) Identify sources of measurement error and bias.
c) Establish direct causality.
d) Maximize external validity.
e) Reject the alternative hypothesis.
a
Studies may be conducted to generate or test hypotheses. The “Gold Standard” for testing a hypothesis is a:
a) Case-control study
b) Cross-sectional survey
c) Longitudinal ecological study
d) Randomized controlled trial
e) Retrospective cohort study
d
The members of a public health team have a continuing interest in controlling measles infection through vaccination. To estimate the level of immunity in a particular population in a quick and efficient manner, what type of study should they conduct?
a) Case-control study of measles infection
b) Cross-sectional survey of vaccination status
c) Randomized trial of measles vaccination
d) Retrospective cohort study of measles vaccination
e) Ecological study of measles in the population
b
A case‐control study may have a particular advantage over a cohort study when the disease in question is:
a) Fatal
b) Indolent
c) Infectious
d) Virulent
e) Rare
e
A cohort study may have a particular advantage over a case‐control study when the disease in question is: COMMON
A clinical research team recommends symptomatic treatment for a clinical toxidrome which has been shown to be effective in animal models. Now the team will test multiple dose levels of the FDA approved drug in a very small group of volunteers. Which of the designs would yield the most information and why?
Latin square because it effectively limits the number of ______(I don’t know what this last part is supposed to say) BUT THE ANSWER IS Latin square.
In Study 7B, the relative risk of skydiving among the exposed is:
3.6
A team of researchers hypothesize that watching “Barney” might lead to epilepsy in childhood. Children with and without epilepsy are compared on the basis of hours spent watching “Barney.” Which of the following statements best characterize the assessment of data in a study such as this?
a) Absolute and relative measures of risk can be derived
b) Risk factor status is the basis for comparison
c) The risk ratio cannot be calculated directly
d) The temporal association between exposure and outcome can be established with certainty
e) The use of healthy controls ensures external validity
c
The researchers in the previous question do not find statistically significant evidence that “Barney” produces epilepsy in childhood. Unwilling, however, to relinquish their line of reasoning, they hypothesize that the parents of children who watch “Barney” are more likely to develop migraine headaches. They assemble two groups of parents: one with children who watch “Barney” and one with children who destroy furniture instead of watching “Barney.” Which of the following is a characteristic of a study such as this?
a) Additional risk factors cannot be assessed as the study progresses
b) Internal validity is independent of confounders
c) Risk factor status does not serve as the basis for comparison
d) The relative risk cannot be calculated directly
e) The temporal association between exposure and outcome is uncertain
a
The risk of acquiring infection beta is 312 per 1000 among the unvaccinated and 7.2 per 1000 among the vaccinated. Approximately 80% of the population is exposed to the pathogen every year. Which of the following actions taken to develop policy would be incompatible with this information?
a) Consideration of the clinical significance (severity) of infection
b) Consideration of the cost of universal vaccination
c) Consideration of the side effects of vaccination
d) Reporting a risk reduction of 304.8 per 1000 attributable to vaccination
e) Reporting that the PAR% is 27
e
The likelihood ratio associated with the use of CK levels for the diagnosis of myocardial infarction varies with the?
a) Cutoff point
b) Degrees of freedom
c) Posterior probability
d) Value of alpha
e) Value of beta
a
As the sensitivity of a test increases, which of the following generally occurs?
a) The cutoff point decreases
b) The false-negative error rate increases
c) The false-positive error rate increases
d) The specificity increases
e) The statistical power decreases
c
Two radiologists interpret 100 mammograms. They agree that the results are normal in 70 mammograms and abnormal in 12 mammograms. In the remaining 18 cases, the first radiologist thinks that results are normal in 6 mammograms and abnormal in 12 mammograms, whereas the second radiologist thinks just the opposite. The value of an appropriate measurement of their agreement is (5 minutes on calculator!):
a) 6%
b) 16%
c) 26%
d) 46%
e) 86%
d
for cell a = [(a+b)(a+c)]/(a+b+c+d) =[(12+6)(12+12)]/(12+6+12+70) =4.32
for cell d = [(c+d)(b+d)]/(a+b+c+d)= [(12+70)(6+70)]/(12+6+12+70) =62.32
Based on the above numbers, the Ac and kappa can be calculated:
Ac=4.32+62.32 = 66.64
Kappa = (82-66.64)/(100-66.64) = 0.46 = 46%
Which of the following characteristics is most important in a screening test that is used to rule out a diagnosis?
a) A high degree of sensitivity
b) A high degree of specificity
c) A low false-negative error rate
d) A reasonable cost
e) Precision
a
Following the onset of blindness resulting from diabetic retinopathy, a 54‐yr old man seems depressed. When you question him regarding the quality of life, he dejectedly tells you that 10 yrs “like this” is not worth 1 yr of good health. His statement indicates:
a) His adjusted life expectancy is 76 years
b) His healthy life expectancy is 76 years
c) His healthy life expectancy cannot be calculated if he actually is depressed
d) Each year of his life contributes less than 0.1 QALY
e) Each year of his life contributes 10 QALY
d
Measures of health status traditionally have been based on mortality data but more recently on chronic diseases. The principal reason this is no longer satisfactory to focus on mortality is that:
a) Changes in diagnostic technology permit earlier detection of disease.
b) The infant mortality rate has declined so much that it no longer serves as a useful index.
c) The population is older and more subject to chronic illness than in the past.
d) There is less risk of fatal infection than in the past.
e) Traditional sources of mortality data have failed to include relevant subpopulations
c
Visceral protein malnutrition that tends to occur in developing nations during the weaning of children from breast milk is known as:
a) Anabolism
b) Anasarca
c) Cachexia
d) Kwashiorkor
d
Of the following environmental hazards, the only one categorized as a nonthreshold hazard is:
a) Carbon monoxide
b) Heat
c) Ionizing radiation
d) Lead
e) Noise
c
A modified influenza vaccine must be produced every year because of the antigenic drift of the influenza virus. of the following is appropriate for determining the efficacy of the vaccine for a particular year?
a) A randomized field trial
b) A retrospective cohort study
c) Administration of the vaccine by random assignment
d) Review of data from previous years
e) Routine surveillance
b
