Epi clicker questions Flashcards
Epidemiology is broadly defined as the study of factors that influence the health population. The application of epidemiologic findings in populations to decisions in the care of individual patients is:
- Generally inappropriate
- Limited to chronic disease epidemiology
- Limited to infectious disease epidemiology
- Known as clinical epidemiology
- Subject to the ecologic fallacy
4
A study involves tracking a condition that can recur in individuals over time. Which of the following measures would allow the authors of the study to make full use of their collected data?
- Attributable risk
- Incidence density
- Period prevalence
- Point prevalence
- Proportional hazards
2
During a given year, 12 cases of disease X are ___________________ reportedly of 70,000 college students. Many more students have mild symptoms of the disease, such as persistent daydreams about selling cocunuts on a Caribbean beach.
Of the 12 detected cases, 7 result in death. The ratio of 7/12 represents:
1. The case fatality ratio
2. The crude death rate
3. The pathogenecity
4. The standardized mortality ratio
5. Prevalence
1
To report the incidence rate of disease X, it would be necessary to know:
- Nothing more than the data provided
- The age distribution of the population
- The case fatality ratio
- The duration of the clinical illness
- The midyear population at risk.
5
To report the prevalence of disease X, it would be necessary to know:
- The cure rate
- The duration of illness
- The number of cases at a given time
- The number of losses to follow-up
- The rate at which new cases developed
3
In the Eastern Siberian encephalomyelitis paper from Epidemiology, there was a redefining of the case diagnosis prior to the extensive follow up surveillance study. Similar to the AIDs 1993 change in diagnosis criteria, these can affect the prediction of the burden of disease by which of the following?
- Prevalence is not conceptually a product of incidence and disease duration
- If the case definition changes, then the recorded incident cases changes
- If the case definition changes, disease prevalence is not affected
- Case definition will not change the actual burden of disease nor our interpretation of the effect on society
- For HIV/AIDs, unlike the Siberian study, not all cases received revised review and the interpretations of disease burden are the same pre- and post-1993
2
Time, distance, and place help to characterize an outbreak and define the natural disease etiology. Which statement of surveillance methodology was supported by the post-hoc active surveillance of the Siberian encephalomyelitis?
- By reviewing every known case and interviewing every known survivor, the possibility of an infectious cause was ruled out
- Genetics was not implicated as causal even though there were more households with multiple cases than expected
- It is possible for an endemic outbreak to become an epidemic, but if it does, it is likely to go pandemic
- Mapping of the spread of incident cases always demonstrates public ____ks through virulence
2
When generating hypotheses regarding causality, as demonstrated in the Siberian encephalomyelitis, evaluating alternate hypotheses would NOT include which one of the following:
- Pick one possible cause (e.g., infectious, genetic, environmental, ecologica, immunological, and social factors)
- Determining a source of infection
- Mapping the pattern of spread
- Investigating the mode of transmission
- Considering fomites such as doorknobs
1
An outbreak of disease should be reported to the local or state health department:
- Under all circumstances
- If the disease is infectious
- If the disease is serious
- If the outbreak involves at least 10 people
- If the diagnosis is uncertain
1
AZ, CO, and NM 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?
- It is an epidemic
- It is an example of active surveillance
- It is not an outbreak because the condition may be endemic
- It is attributable to improved surveillance
- It is appropriately investigated by the CDC
5
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?
- The clinical features and methods of diagnosing the disease
- The usual disease patterns and reporting practices
- The exact location and timing of disease onset
- The incubation period and pattern of disease transmission
- The disease vector and resivoir
2
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:
- Case finding
- Active surveillance
- Outbreak investigation
- Screening
- Secondary prevention
2
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 magazines, 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 case of Lyme borreliosis. This represents:
- A change in reporting that would underestimate prevalence
- Active surveillance
- A change in surveillance that would overestimate the liklihood of an outbreak
- A change in surveillance that would have an unknown effect
- Recall bias
4
The BEINGS model provides a list of factors in disease causality. Which of the following factors are explicitly included in:
- Behavioral, ecological, immunologic, nutritional, genetic, and synergistic factors
- Biological, environmental, immunologic, nutritional, genetic, and service factors
- Behavioral, ecological, immunologic, nutritional, genetic, and selective factors
- Biological, environmental, innate, nutritional, genetic, and synergistic factors
- Behavioral ecological, idiopathic, nutritional, genetic, and social factors
2
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:
- Confounding
- Recall bias
- Random error
- Misclassification
- Spectrum bias
2
The basic goal of epidemiologic research is to:
- Eliminate all bias
- Compare two groups that differ in terms of exposure or outcome
- Establish causality
- Maximize external validity
- Reject the null hypothesis
2
Studies may be conducted to generate or test hypotheses. The best design for testing a hypothesis is a:
- Case-control study
- Cross-sectional survey
- Longitudinal ecologic study
- Retrospective cohort study
- Randomized controlled trial
5
The members of a public health team have a continuing interest in controlling measles infection through accination. 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
- A randomized trial of measles vaccination
- A cross-sectional survey of vaccination status
- A retrospective cohort study of measles vaccination
- An ecologic study of measles in the population
3
A case-control study may have a particular advantage over a cohort study when the disease in question is:
- Fatal
- Rare
- Infectious
- Indolent
- Virulent
2
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 small group of volunteers. Which of the design would yield the most information and why?
- A case-control study of because it eliminates selection bias
- A randomized trial because it tests the hypothesis
- A cross-sectional survey because it adds experimental power
- A retrospective cohort study because it allows post-hoc comparisons
- A Latin square study because it efficiently limits the number of subjects needed
5
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 confounder
- A necessary cause
- An effect modifier
- A sufficient cause
- A risk factor
3
In the relationship between obesity and cardiovascular disease, what are hyperlipidemia and hyperglgycemia?
- Confounders
- Effect modifiers
- Intervening variables
- Necessary causes
- Unrelated
3
What is the relationship of asbestos to asbestosis?
- Confounder
- Effect modifier
- Necessary cause
- Sufficient cause
- Synergism
3
I didn’t ask for the RR for Study 6A prior to 6B because it would not be appropriate. So regarding 6A, which of the following statements is correct? (From lecture slides)
- Jumpers and non-jumpers should be matched for beverage consumption
- The AR and RR of jumping can be determined from 6A
- 6A is a cohort study
- Can calculate an OR for 6A but not RR
- Unanticipated outcomes can be assess in this study
4
In study 6B, the relative risk of skydiving amount the exposed is (from lecture slides):
- 2.12
- 3.6
- 4.8
- 6
- 115
2
The clinicians in a primary care clinic do not know the prevalence of Chlamydia trachomatis infection in their community. In screening patients for this infection, they plan to use a test that performed with a sensitivity of 75% and a specificity of 75% in clinical trials. What is the value for the LR+ from the previous question.
- 2.6
- 5
- 3
- 16
- 8.4
3
The clinicians in a primary care clinic do not know the prevalence of Chlamydia trachomatis infection in their community. In screening patients for this infection, they plan to use a test that performed with a sensitivity of 75% and a specificity of 75% in clinical trials. When the clinicians use the test to screen patients for C. trachomatis in their own community, which of the following could they use to help them interpret a positive test result?
- Kappa
- Phi
- LR+
- Odds ratio
- RR
3
As the sensitivity of a test increase, which of the following generally occurs?
- The cutoff point decreases
- The false-positive error rate increases
- The false-negative error rate increases
- The specificity increases
- The statistical power decreases
2
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?
- Absolute and relative measures of risk can be derived
- Risk factor status is the basis for comparison
- The risk ratio cannot be calculated directly
- The temporal association between exposure and outcome can be established with certainty
- The use of healthy controls ensures external validity
3
The researchers in the previous question do not find it statistically significant evidence that “
Barney” produces epilepsy in childhood. Unwilling, however, to relinquizsh their line of reasoning, they hypothesize that the parents of children who watch “Barney” are more likely to develop migraine headaches. The 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 study such as this?
1. Additional risk factors cannot be assessed as the study progresses
2. Internal validity is independent of confounders
3. Risk factors status does not serve as the basis for comparison
4. The relative risk cannot be calculated directly
5. The temporal association between exposure and outcome is uncertain
1
Which of the following characteristics is most important in a screening test that is used to rule out a diagnosis?
- Precision
- A reasonable cost
- A low false-negative error rate
- A high degree of specificity
- A high degree of sensitivity
5
Which study would be most useful when comparing an infection with and without safety measures?
Cohort study
A study with 2.5 infections per 100,000 people developed during a time period is called what?
Incidence rate
What type of study is described when drugs are randomly assigned therapy?
RCT
What regularity of mortality were from causes other than plague?
Deaths from plague were suspected to be environmental cause
An individual is the first infected with the disease during the week of July 15th, what is this called?
Sentinel case
The application of epidemiology in populations to decisions in the care of medical patients and patient populations in health care is what?
Clinical epidemiology
The BEINGS model is a useful paradigm for what?
Evaluation of etiologic factors in disease
The B and the E in the BEINGS model stand for what?
B stands for behavioral, while E stands for environmental
Herd immunity is what?
Prevention of disease transmission to susceptible individuals through acquired immunity in others
A study involves tracking individuals over time to make full use of collected data, what is it?
Incidence density
Of 12 detected cases, 7 resulted in death. The ratio of 7/12 represents what?
Case fatality ratio
To report incidence rate of disease X, it would be necessary to know what?
The midyear population at risk
To report the prevalence of disease X, it would be necessary to know what?
Number of cases at a given time
What percent of death certificate diagnosis are thought to be potentially inaccurate?
15-20%
By reviewing every known case of encephalomyelitis and summer interviews, the possibility of what occurred?
Genetics was not implicated as the cause even though there were more known households with multiple cases of positive infection
When generating hypothesis regarding causality as in the encephalitis case, evaluating an alternative hypothesis would not include what?
Pick one cause
The outbreak of a disease should be reported to local or state health departments under what?
All circumstances
AZ, CO, and NM report unexplained RTIs with high case fatality ratios. Which is reliably true regarding this event?
It is appropriately investigated by the CDC
Cases of flesh eating group A strep was reported in a defined population. Which type of information would be most helpful to determine if these cases represent disease outbreak?
The usual disease patterns and reporting practice
An official from the state department of public health visits outpt clinics and EDs to determine the number of cases of PEP for rabies. The official’s action is an example of what?
Active surveillance
Article highlighting the long term consequences of inadequately treated Lyme’s disease were published in a medical journal. Cases in which physician diagnosed Lyme’s disease where test results are positive were reported as cases of Lyme borreliosis. This represents what?
A change in surveillance that would have an unknown effect
When questioned years after illness, individuals served as cases reported move severe subjective symptoms than those of the control. This is probably an example of what?
Recall bias
The basic goal of epidemiology research is to do what?
Compare two groups that differ in terms of exposure or outcomes
Studies that may be conducted to generate or test hypothesis, the best design for testing a hypothesis is what?
RCT
The members of a public health team controlling measles infections through vaccines are to estimate the level of immunity in a particular population in a quick and efficient manner. What type of study should they conduct?
Cross-sectional survey of vaccine status
Case control studies may have advantages over cohort studies when the disease in question is what?
Rare
A clinical research team recommends symptom treatment for a clinical toxidrome shown to be effective in animals. Now a team is to test multiple doses of the FDA approved drug in a small study group. What is the best way to do this?
Latin square
Among the elderly who are fit, exercise reduces heart disease. If initiated, exercise is an example of what?
Effect modifier
In the relationship between obesity and CVD, what are hyperlipidemia and hyperglycemia?
Intervening variable
What is the relationship between asbestos to asbestosis?
Necessary cause
As sensitivity of a test increases, which generally occurs?
False positive error rate increases
Which of the following characteristics is most important in a screening test used to rule out diagnosis?
High degree of sensitivity
When clinicians use the test to screen patients for C. trachomatis in our community, which could they use to help them interpret a positive test result?
LR+
What is the value of LR+ from the previous question (sensitivity is 75% and the specificity is 75%)?
3
