Epi Final

Two hundred people attended a church supper. The next day, 30 people reported vomiting 4 to 7 hours after the supper. What was the attack rate of illnesses for people attending the supper? 20% 30% X 15%

15%

An outbreak of salmonellosis occurred after an epidemiology department luncheon, which was attended by 485 faculty and staff. Assume everyone ate the same food items. Sixty-five people had fever and diarrhea, five of these people were severely affected. Subsequent laboratory tests on everyone who attended the luncheon revealed an additional 72 cases. The attack rate of salmonellosis was:

28.2

A screening examination was performed on 250 persons for Factor X, which is found in disease Y. A definitive diagnosis for disease Y among the 250 persons had been obtained previously. The results are charted below: RESULTS OF DIAGNOSIS TEST RESULTS Disease Present Disease Absent Positive for Factor X 40 60 Negative for Factor X 10 140 What is the sensitivity of this test?

80%

Measles are extremely infectious and 900 of 1,000 people who come into contact with the virus will become ill with a fever and a rash. For every 1,000 people with measles, 300 will have one or more complications. Sixty cases will develop pneumonia, one case will have encephalitis, and two cases will die. Considering these statistics, what is the pathogenicity of measles? 0.10% 6% 30% X 90%

90%

Which of the following is true for a confounder? A. Must be a risk factor (or protective factor) for disease B. Must be associated with the exposure C. Must be an intermediate step in the exposure-disease pathway Correct! D. A and B only E. A, B, and C

A and B only

The "Epidemiologic Triangle" is:

A framework for conceptualizing the determinants of disease as related to host, agent, and environmental factors

Which of the following factors can influence the stress-illness relationship? A. Type A behavior pattern B. Social support C. Personal behaviors D. A and B only Correct! E. A, B, and C

A, B, and C

Which of the following is not a method for controlling the effects of confounding in epidemiologic studies? Randomization Stratification Matching x Blinding Restriction

Blinding

What is the most common cancer diagnosed among New Jersey women in 2017? Lung and bronchus X Breast Colon and rectum Corpus and uterus, NOS

Breast

Subjects for an exposure-based cohort study would be selected most appropriately from:

Certain occupational groups such as battery workers for studying lead exposure

Information about the cause of death listed on a death certificate may be unreliable because: a) The cause of death may be unclear b) Certain diseases carry a stigma c) Assignment of the cause of death may be incorrect Correct! d) All of the above

Correct! d) All of the above

Place each of the following field investigation steps in the correct order Correct!1 Prepare to go into the field Correct!2 Verify the epidemic Correct!3 Define and identify cases Correct!4 Describe data according to person, place, and time Correct!5 Develop and test hypotheses Correct!6 Implement control/prevention measures

Correct!1 Prepare to go into the field Correct!2 Verify the epidemic Correct!3 Define and identify cases Correct!4 Describe data according to person, place, and time Correct!5 Develop and test hypotheses Correct!6 Implement control/prevention measures

Match each of the following trends of disorders with the appropriate definition or example:

Correct!Disappearing Thanks to vaccination efforts, Polio is no longer present in epidemic form Correct!Residual Although causal factors are now known, STIs are still present Correct!Persisting Causal factors for some developmental disorders are largely unknown Correct!New Epidemic HIV/AIDS in the 1980s

Match each of the following surveillance types with the appropriate characteristic:

Correct!Passive Surveillance: Inexpensive, but subject to under-reporting Active Surveillance: Accurate, but expensive and time-consuming Sentinel Surveillance:The first case of a disease warns of a possible outbreak Syndromic Surveillance: Cases identified based on symptoms, not definitive diagnosis

Match each epidemic type with the appropriate epidemic curve shape

Correct!Point source: Rapid rise to a peak, then gradual decline Correct!Continuous common source: Gradual rise to a plateau Correct!Propagated :Multiple, progressively taller peaks

Match each of the following types of prevention with the appropriate example:

Correct!Primary Prevention Education aout the risks of IV drug use Correct!Secondary Prevention HIV screenin test in IV drug users Correct!Tertiary Prevention Anti-retroviral medication to treat HIV

In relation to screening programs, match the term on the left with the definition on the right: Correct!Selection bias: Individuals that participate in screening programs may be generally healthier and have a different probability of disease than those who do not participate Correct!Length bias: Cases detected by a screening program tend to be slower growing and less aggressive, while faster growing cases appear clinically faster Correct!Lead time bias: Because of screening, cases appear to have a longer survival simply because the disease was identified earlier in the natural history of the disease Correct!Overdiagnosis bias: Because of enthusiasm for a new screening program, higher rates of false positives give a false impression of increased diagnosis and unrealistically favorable outcomes

Correct!Selection bias: Individuals that participate in screening programs may be generally healthier and have a different probability of disease than those who do not participate Correct!Length bias: Cases detected by a screening program tend to be slower growing and less aggressive, while faster growing cases appear clinically faster Correct!Lead time bias: Because of screening, cases appear to have a longer survival simply because the disease was identified earlier in the natural history of the disease Correct!Overdiagnosis bias: Because of enthusiasm for a new screening program, higher rates of false positives give a false impression of increased diagnosis and unrealistically favorable outcomes

Match each stage of the disease process with the correct description:

Correct!Susceptibility (Pre-pathogenesis) Before the disease process has started Correct!Incubation The elapsed time between onset of the disease process and appearance of symptoms Correct!Clinical Disease The host exhibits physical signs and/or symptoms of disease Correct!Convalescence The period of recovery, when the signs/symptoms (hopefully) resolve

Match each toxicokinetics process with the appropriate definition:

Correct!The substance enters the body: Absorption Correct!The substance moves to other sites in the body: Distribution Correct!The body changes the substance into a new chemical or metabolite: Biotransformation Correct!The body ejects the substance or its metabolite: Excretion

A larger sample size in an epidemiologic study implies all of the following EXCEPT:

Decreased systematic error

Characterizing the distribution of health-related states or events according to person, place, and time is:

Descriptive epidemiology

What is one of the widely used sources of statistical data on cancer?

Disease registries

A graph that is used to assess the effect of exposure to a chemical or toxic substance upon an organism X Dose response Threshold Latency Synergism

Dose response

A case-control study is purely a descriptive (as opposed to analytic) study design.

False

A cross-sectional study allows the demonstration of a time sequence between exposure and disease.

False

A reliable measurement tool always yields valid results.

False

Health insurance statistics provide a representative picture of the health status of the United States population.

False

If, when testing the significance of a risk factor for a disease, the result is highly statistically significant, then that risk factor must be an important factor for the disease.

False

It is possible for a measure to be valid but unreliable. TRUE XFALSE

False

About 4 hours after eating at a local restaurant, Bob began vomiting profusely. His symptoms lasted about 6 hours and he never developed a fever. Bob most likely suffered from: Correct!

Food-borne intoxication

Waldron's research found that reason(s) for gender differences in mortality include:

Greater frequency of smoking among men

When a toxin is observed to have beneficial health effects at low doses, this is called:

Hormesis

Which of the following are false: Ecologic analysis uses data on groups, not individuals X In case control studies, the initial selection is based on exposure Cross sectional studies cannot establish temporality X Retrospective cohort studies are not subject to recall bias

In case control studies, the initial selection is based on exposure Retrospective cohort studies are not subject to recall bias

For 2003, Alaska reported 15 new cases of salmonellosis per 100,000 people. This is an example of: Prevalence Attack rate X Incidence rate

Incidence rate

A mother and child were exposed to E. coli O157:H7 on October 22, but didn't show syptoms until October 28. What do you call the time period between exposure and onset of symptoms? Exposure time X Incubation period Period of infectiousness Outbreak interval

Incubation period

How likely the agent will be transmitted is called X Infectivity Pathogenicity Virulence

Infectivity

Blinding in a prospective study can reduce

Information Bias

In a case-control study to investigate the association between lung cancer and second-hand smoke, you learn that second-hand smoke exposure was over-reported among the cases, but not controls. This is an example of:

Information bias

The time period between initial exposure and a measurable response Dose response Threshold X Latency Synergism

Latency

Which of the following terms is expressed as a ratio (as distinguished from a proportion or rate)?

Male births / Female births

Which of the following data sources could be useful for estimating prevalence of certain risk factor behaviors in the general population?

National Health Interview Survey

How likely the agent will make its host sick is called Infectivity X Pathogenicity Virulence

Pathogenicity

ou have just finished administering a food/drink questionnaire to ill and non-ill participants in a Minnesota summer picnic party. The ill individuals developed moderate to severe diarrhea 16 to 46 hours after the picnic. Six persons experienced vomiting. The following data were collected: ATE DID NOT EAT Number of people Number of people Food item Ill Not ill Total Ill Not ill Total Hot dogs 40 30 70 10 20 30 Hamburgers 32 8 40 20 40 60 Potato salad 48 12 60 2 38 40 Ice cream 45 25 70 15 25 40 Lemonade 20 40 60 20 20 40 Which food item appears to be the most probable vehicle for the salmonella (agent) infection associated with the illness?

Potato salad

You work for a local health department and need to calculate a measure that includes numbers of both new and existing HIV cases. Which would you choose: X Prevalence Incidence rate Attack rate

Prevalence

What is the most common cancer diagnosed among New Jersey men in 2017? Urinary bladder Colon and rectum Lung and bronchus X Prostate

Prostate

The association between induced abortion and breast cancer has been the subject of several epidemiological studies. Cohort studies have found no association, while at least one case-control study has found a positive association. Possible explanations for the different results in case-control and cohort studies of this topic include.

Recall bias might explain the association observed in a case-control study, but this would not be a problem in prospective cohort studies

Herd Immunity may be defined as:

Resistance of a group to an attack by a disease to which a large proportion of the members of the group are immune.

It has been suggested that occupational exposure to benzene in the petroleum industry increases the risk of developing leukemia. The levels of benzene to which workers in this industry have been exposed were high from 1940 to 1970, but since 1970 have been significantly reduced. What kind of study design, using petroleum workers, would provide the most useful information on whether benzene affects incidence rates of leukemia in this industry? You may assume that records of individual worker assignments to jobs involving benzene exposure have been maintained by the industry.

Retrospective cohort

In a case-control study to investigate the association between lung cancer and second-hand smoke, you learn that the prevalence of second-hand smoke exposure among the participating control subjects is much higher than it is in the general population (the study base). This is an example of:

Selection bias

Rachel Carson is famous for: Her work with Salk in developing a polio vaccine She surveilled occupational diseases, the "mother of occupational epidemiology" X She wrote "Silent Spring" launching the modern environmental movement She was the first to identify DDT as an environmental problem

She wrote "Silent Spring" launching the modern environmental movement

Which of the following is a way to control for confounding in the analysis phase of a study? A. Matching B. Restriction Correct! C. Stratification D. Randomization

Stratification

A situation in which the combined effect of several exposures is greater than the sum of the individual effects Dose response Threshold Latency X Synergism

Synergism

The incidence of a disease is five times greater in men than in women, but the prevalence shows no sex difference. The most likely explanation is:

The duration of the disease is greater in women

The major disadvantage of crude rates is that:

They do not permit comparison of populations that vary in composition.

The lowest dose at which a particular response may occur Dose response X Threshold Latency Synergism

Threshold

A registry is a centralized database of information about a disease.

True

An ecologic comparison study (aka a cross-sectional ecologic study) assesses the correlation between exposure rates and disease rates among different groups or populations over the same period of time.

True

An ecologic study is one that examines a group as a unit of analysis.

True

Controls are needed in a case-control study to evaluate whether the frequency of a factor or past exposure among the cases is different from that among comparable persons who do not have the disease under investigation.

True

The "no effect" (null) value of the relative risk is 1.

True

The point prevalence of a disease is defined as the number of persons ill divided by the total number in the group at a point in time.

True

The purpose of matching in a case-control study is to select the controls in such a way that the control group has the same distribution as the cases with respect to certain confounding variables.

True

Validity is the ability of a measuring instrument to give a true measure. XTRUE FALSE

True

When the duration of a disease becomes short and the incidence is high, the prevalence becomes similar to incidence. Correct!

True

How likely the agent will cause severe illness or death in its host is called Infectivity Pathogenicity X Virulence

Virulence

Which of the following is a challenge cancer registries face? Obtaining complete and accurate data Timely reporting Staying current on changes in data standards X All of the above

X All of the above

A mother and their 3-year old child were recently infected by E.coli O157:H7 infections. What are the possible types of transmission to consider? X Horizontal - direct X Horizontal - indirect Vertical

X Horizontal - direct X Horizontal - indirect

Australia and New Zealand have some of the highest overall cancer incidence rates. This is primarily driven by: Marsupials spread a microbe endemic to the area The diet is highest per capita in red meat consumption X Large proportion of the population is white and there is lots of sun High arsenic levels in the groundwater

X Large proportion of the population is white and there is lots of sun

Asbestos was banned in 1989. What could lead to high rates of pneumonniocosis in NJ? X Latency X Asbestos sites and products produced before 1989 still exist Mining in NJ X Manufacture of asbestos products in NJ

X Manufacture of asbestos products in NJ X Asbestos sites and products produced before 1989 still exist X Latency

Which of the following are true: DDT is an organophosphate X Methyl mercury is more toxic than inorganic mercury Asbestos is associated with Black Lung Disease X Hormesis occurs when a low does of a toxi actually improves health

X Methyl mercury is more toxic than inorganic mercury X Hormesis occurs when a low does of a toxi actually improves health

Which of the following is NOT required by the NJ cancer registry statute? Reporting of all cancer cases diagnosed or treated in NJ Reporting by all NJ health care providers and independent clinical laboratories X Reporting immediately after diagnosis Electronic reporting

X Reporting immediately after diagnosis

Which of the following is NOT a purpose of a cancer registry? X To function merely as a data warehouse To help researchers determine cancer patterns in a population To help governments prioritize the alocation of health resources To help advance clinical, epidemiological, and health services research

X To function merely as a data warehouse

A sentinel health event refers to:

a case of unnecessary workplace disease that serves as a warning signal.

Choose the incorrect answer. The current Decennial U.S. Census: Correct! a) Administers a detailed questionnaire to a subset of the population b) Attempts to account for every person in the country c) Is administered every ten years d) Characterizes the population according to demographic variables

a) Administers a detailed questionnaire to a subset of the population

Asbestos exposure has been associated with:

asbestosis, malignant , and lung cancer

The purpose of a double-blind study is to: achieve comparability of cases and controls. reduce the effects of sampling variation. avoid observer and interviewee bias. avoid observer bias and sampling variation. avoid interviewee bias and sampling variation.

avoid observer and interviewee bias.

Marital status is an important descriptive epidemiologic variable because it is: a) Associated with high suicide rates among married females b) Theorized to be a selective factor in health c) Theorized to be a protective factor in health Correct! b and c

b and c

Which of the following is NOT one of the four criteria for the utility of epidemiologic data? a) The nature of the data b) The completeness of the data Correct! c) The reason the data were collected d) The availability of the data

c) The reason the data were collected

Exposure to electric and magnetic fields has been linked to:

childhood leukemia risk

An observed increase of prostate cancer incidence over time may be due to: a) Improved screening and diagnostic tests b) Changes in screening recommendations c) A true increase in prostate cancer incidence Correct Answer d) All of the above

d) All of the above

A new hypertension drug was compared with placebo in a double-blind clinical trial. Which of the following best describes the primary reason(s) for a "double-blind" design? a) To create two treatment groups that are similar at baseline on known and unknown factors associated with hypertension b) To prevent bias introduced when the patients know what type of treatment they are receiving c) To prevent bias introduced when the investigators know what type of treatment the patients are receiving Correct! d) Both b and c

d) Both b and c

The definition of epidemiology includes the following: a) Study of the distribution of disease in the population b) Study of the determinants of disease in the population c) Applying the findings from a) and b) to the control of health problems Correct! d) a, b, and c

d) a, b, and c

When choosing a data source, one should consider the completeness of the data. This refers to a) The degree to which the data are representative of a parent population b) The degree to which results are applicable to the target population c) The degree to which the data include all cases of a given disease Correct! d) a, b, and c

d) a, b, and c

Which of the following reasons might account for place variation in disease? a) Genetic and environment interactions b) Influence of climate c) Presence of environmental carcinogens Correct! d) a, b, and c

d) a, b, and c

What data source(s) has the advantage of being almost nearly complete in the U.S.? a) Reportable disease statistics b) Mortality statistics c) Birth statistics Correct! d) b and c

d) b and c

Descriptive epidemiology characterizes the amount and distribution of disease within a population and enables the researcher to: a) Make direct tests of etiologic hypotheses b) Generate testable hypotheses regarding etiology c) Evaluate trends in health and disease within a population Correct! d) b and c only

d) b and c only

One must use care in interpreting occupational differences in morbidity and mortality because:

good health status may be a factor for selection into a job.

The healthy worker effect refers to the observation that:

healthy persons are more likely to gain employment than unhealthy persons.

The adverse consequences of using a screening test that has a low specificity include i. unnecessarily subjecting people to potential risks associated with diagnostic procedures ii. overreferral of persons without disease for diagnosis iii. increasing the number of persons who are classified as abnormal iv. failure to identify persons who have the condition Which of the above statements are correct?

i, ii, and iii only

An epidemiological experiment is performed in which one group is exposed to a suspected factor and the other is not. All individuals with an odd hospital admission number are assigned to the second group. The main purpose of this procedure is to:

improve the likelihood that the two groups will be comparable with regard to known and unknown confounding factors.

A double-blind study of a vaccine is one in which: the study group receives the vaccine and the control group receives a placebo. neither observers nor subjects know the nature of the placebo. x neither observers nor subjects know which subject receives the vaccine and which receives a placebo neither the study group nor the control group knows the identity of the observers. the control group does not know the identity of the study group.

neither observers nor subjects know which subject receives the vaccine and which receives a placebo

The strategy which is NOT aimed at reducing selection bias is: development of an explicit case definition. encouragement of high participation rates. Correct! standardized protocol for structured interviews. enrollment of all cases in a defined time and region.

standardized protocol for structured interviews.

Appetite loss is an example of a

symptoms

A situation in which the combined effect of several exposures is greater than the sum of the individual effects:

synergism

The lowest dose at which a particular response may occur:

threshold

A dynamic population is one that adds new members through immigration and births and loses members through emigration and deaths.

true

Reliability refers to the ability of a measuring instrument to give consistent results on repeated trials, regardless of its accuracy. TRUE FALSE

true

Which of the following is a technique to reduce information bias? Use memory aids and validate exposures. Provide standardized training sessions and protocols. Use standardized collection forms. Try to ensure that questions are clearly understood. x All are correct.

x All are correct.

In a study to determine the incidence of a chronic disease, 150 people were examined at the end of a three-year period. Twelve cases were found, giving a cumulative risk of 8%. Fifty other members of the initial cohort could not be examined; 20 of these 50 could not be examined because they died. Which source of bias may have affected the study? Information bias: interviewer/abstractor bias Hawthorne effect x Selection bias: survival bias Information bias: recall bias

x Selection bias: survival bias

You are investigating the role of physical activity in heart disease and suggest that physical activity protects against having a heart attack. While presenting these data to your colleagues, someone asks if you have thought about confounders such as factor X. This factor X could have confounded your interpretation of the data if it: is a factor for some other disease, but not heart disease. x is a factor associated with physical activity and heart disease is a part of the pathway by which physical activity affects heart disease. has caused a lack of follow-up of test subjects

x is a factor associated with physical activity and heart disease