Epi Exam 2

Stochastic process

A process that incorporates some element of randomness

SEER

Conducted by the NCI, collects cancer data from different cancer registries across the US

Cohort effect

Consequence of long-term secular trends in exposure within a specific cohort

Case Clustering

Denotes an unusual aggregation of health events grouped together in space or time.

Population risk difference

Difference between the incidence rate of a disease in the nonexposed segment of the population and the overall incidence rate. It measures the benefit to the population derived by modifying a risk factor

A

If the exposure is considered the cause of disease, which measure can be used to calculate the number of disease cases that would be eliminated if the exposure were eliminated? A. Risk difference ("Attributable risk") B. Attributable proportion among the exposed ("attributable fraction") C. Risk Ratio D. Proportional Mortality Ratio

Variety

Incorporating data from disparate sources into a single data set.

D

Morbidity surveys of the general population: A. Typically use a scientifically designed representative sample B. Include the Health and Nutrition Examination Survey C. Collect data on the health status of a population group D. All are correct

Privacy Act of 1974

Prohibits the release of confidential data without the consent of the individual

True

T/F: A registry is a centralized database of information about a disease.

Sampling unit

That element or set of elements considered for selection in some stage of sampling

Generalizability

The ability to apply findings to a population that did not participate in the study.

B

The use of GIS may be thought of as following the heritage of: A. Semmelweis B. Snow C. Graunt D. Hippocrates E. Koch

Individual matching

To match each case with one or more controls who are the same age and gender

Ecologic comparison studies (cross-sectional ecologic studies)

Type of research design that assesses the correlation between exposure rates and disease rates among different groups or populations over the same time period. The unit of analysis is the group.

Probability sample

Type of sample in which every element in the population has a nonzero probability of being included in the sample

Non probability sample

Type of sample in which the population does not have a nonzero probability of being included in the sample

Ecologic trend study

Type of study that examines the correlation of changes in exposure and changes in disease over time within the same community, country, or other aggregate unit.

Why are data crucial for epidemiology and public health practice?

-Need to characterize whole populations -Requirement of adequate numbers for statistical reference -Low frequency conditions

Sufficient cause

A cause that is sufficient by itself to produce the effect

Registry

A centralized database for collection of data about a disease

Confidence interval

A computed interval of values that, with a given probability, is said to be contain the true value of the population parameter; a measure of uncertainty about a parameter estimate.

Necessary cause

A factor whose presence is required for the occurrence of the effect

Cohort

A group of individuals who share an exposure in common and who are followed over time; an example is an age cohort

Null hypothesis

A hypothesis of no difference in a population parameter among the groups being compared

A

A large medical center's oncology program reported an increased number of cases of pancreatic cancer during a certain month. The hospital's epidemiologist decided to research the problem. Tumor registry records were searched to identify all cases of pancreatic cancer during a five-year period; cancer patients were matched with patients treated for other diseases during the same five-year period. All subjects in the study were questioned about lifestyle factors including alcohol consumption. What kind of study is this? A. Case- control B. Cross- sectional C. Cohort D. Experimental

Attributable risk

A measure of risk difference. In a cohort study, it refers to the difference between the incidence rates of a disease in the exposed group and the incidence rate in the nonexposed group

Disability- adjusted life years (DALYs)

A measure that adds the time a person has a disability to the time lost to early death; this, one DALY indicates on year of life lost to the combination of disability and early mortality

Ecologic Fallacy

A misleading conclusion about the relationship between a factor and an outcome that occurs when the observed association obtained between study variables at the group level does not necessarily hold true at the individual level.

Wheel model

A model that explains the etiology of disease by calling into play host and environmental interactions

Causal pie model

A model that indicates that a disease may be caused by more than one causal mechanism (sufficient cause)

Web of causation

A popular metaphor for the theory of sequential and linked multiple causes of diseases and other health states

Multiple causation

A portrayal of causation wherein several individual, community, and environmental factors may interact to cause a particular disease or condition.

Effect measure

A quantity that measures the effect of a factor on the frequency or risk of a health outcome

Discordant pairs

A situation in which one member of the pair has been exposed and the other has not

B

A study of binge drinking and depression was conducted by interviewing a random sample of college students. Of the 5,000 students sampled, 90% completed the interview and reported whether they had drunk more than 3 drinks within an hour during the past month or not. These students answered a series of questions about their current mental health. What type of study is this? A. Case- control B. Cross- sectional C. Ecological study D. Intervention trial E. Case- series

Case- Control Study

A study that compares individuals who have a disease with individuals who do not have the disease to examine differences in exposures or risk factors for the disease.

Cross-sectional study (prevalence study)

A type of descriptive study designed to estimate the prevalence of a disease or exposure

Simple random samples

A type of sample in which each individual in the population has an equal probability of being selected

Discrete variable

A variable that has distinct values for each measurement

B

According to classic studies, age- standardized morbidity rates in the United States for acute conditions, chronic conditions, and disability due to acute conditions show the following sex differences: A. Rates for males are equal to rates for females B. Rates for females are higher than rates for males C. Rates for males are higher than rates for females D. Females have higher rates of hearing than males

C

Age- specific and age-adjusted rates by sex in the United States generally show the following sex differences: A. Rates for males are higher than rates for females from age 6 to age 85 and older. B. Rates fro males are equal to rates for females during the first 5 years of life C. Rates for males are higher than rates for females from birth to age 85 and older. D. Rates for females are higher than reates for males from birth to age 85 and older.

D

Aggregated statistics... A. are stripped of individually identifying characteristics before released online publicly B. Include vital statistics C. Follow a chain of collection process from the local up to the international level D. All are true

Case- cohort study

An alternative to a nested case-control study, it involves random selection of controls from the study cohort instead of using matching

Attributable proportion

An approach to estimating the effects due to the single exposure factor; the proportion of the rate in the exposed group that is due to the exposure

P value

An assessment that indicates the probability that the observed findings of a study could have occurred by chance alone

Protective Factor

An influence that reduces the likelihood of adverse consequences from harmful exposures.

A

B Which of the following is the appropriate measure of association for a cross-sectional study? A. prevalence-based relative risk ratio B. Correlational coefficient r C. Odds ratio D. This type of study cannot produce a measure of association

D

Before utilizing data for an epidemiologic study, the researcher must first consider the: A. Nature of the data B. Completeness of coverage C. Availability of the data D. All are correct

Concordant pairs

Both members of a pair have been either exposed or not exposed to the study factor

C

Case- control studies are among the best observational designs to study diseases of: A. low case fatality B. high prevalence C. low prevalence D. high validity

Health Insurance Portability and Accountability Act of 1996 (HIPAA)

Categories of protected health information pertain to individually identifiable data

Deterministic model

Claims that a cause is invariably followed by an effect

Morbidity Surveys

Collect data on the health status of a population group, obtain more comprehensive information than would be available from routinely collected data

D

Cyclic variations in the occurrence of disease may reflect: A. Changes in the risk-taking behavior of persons B. Changes in exposure to infectious agents C. Changes in temporary stressors D. All are correct

A

Descriptive epidemiology characterizes the amount and distribution of disease within a population and enables the researcher to: A. Generate testable hypotheses regarding and evaluate trends in health and disease within a population B. Generate testable hypotheses regarding etiology C. Make direct tests of etiologic hypotheses D. Evaluate trends in health and disease within a population

Case Reports

Detailed accounts of cases and disease among individuals. Helpful in making epidemiologic descriptions of disease.

B

Examples of descriptive epidemiologc studies do not usually include: A. case series B. cohort studies C. cross- sectional studies D. All of these are types of descriptive epidemiologic study designs

Freedom of Information Act

Mandates the release of government information to the public, except for personal and medical files

Descriptive Epidemiology

Portrays the occurrence of disease with respect to the characteristics of person, place, and time.

Etiologic fraction

Proportion of the rate of disease in an exposed group that is due to the exposure

The Public Health Service Act

Protects confidentiality of information collected by some federal agencies

Case Series

Refers to a grouping of cases that share similar adverse health outcomes

Overmatching

Refers to a situation in which the case and controls are too closely matched or matched on too many variables

Temporal Clustering

Refers to clustering of cases in time.

Spatial Clustering

Refers to the concentration of cases of disease within a particular geographic area.

Stratified sampling approach

Requires that the population be divided into mutually exclusive and exhaustive strata; sampling is then performed within each stratum

Descriptive Studies

Studies that characterize the amount and distribution of disease within a population.

Analytic Studies

Studies that explore the determinants of disease, the causes of relatively high or low frequency of diseases in specific populations.

False

T/F: Health Insurance statistics provide a generally representative picture of the health status of the U.S. population

True

T/F: In a case-control study, cases and controls are completes in order to determine whether they differ with respect to their exposure levels.

False

T/F: In the United States, breast cancer is the leading cause of cancer deaths among females

False

T/F: Prevalence of multiple sclerosis varies in latitude in the United States.

False

T/F: The Freedom of Information Act allows the release of personal medical data.

True

T/F: The National Health Survey consists of several distinct programs conducted by the National Center for Health Statistics.

True

T/F: The WHO is a major source of information about worldwide international variations in rates of disease.

False

T/F: The human biological clock phenomenon is linked to place variation in diseases.

True

T/F: The three categories of descriptive epidemiologic variables are person, place, and time.

E

The Vital Statistics Registration System in the United Staes collects data on all vital events including: A. fetal deaths B. births & deaths C. deaths D. births E. All are vital data statistics

Thoroughness

The care taken to identify all cases of a given disease

A

The death rate per 100,000 for lung cancer is 7 among nonsmokers and 71 among smokers. The death reate per 100,00 for coronary thrombosis is 422 among nonsmokers and 599 among smokers. The prevalence of smoking in the population is 55%. On the basis of the relative risk and etiologic fractions associated with smoking for lung cancer and coronary thrombosis, which of the following statements is most likely to be correct. A. Smoking seems much more likely to be causally related to lung cancer than to coronary thrombosis B. Smoking seems to be equally causally related to lung cancer and coronary thrombosis C. Smoking does not seem to be causally related to either lung cancer or coronary thrombosis. D. No comparative statement is possible between smoking and lung cancer or coronary thrombosis E. Smoking seems much more likely to be causally related to coronary thrombosis than to lung cancer

Representativeness

The degree to which a sample resembles a parent population

Systematic sample

The procedure selecting according to some simple, systematic rule, such as all persons whose names begin with specified alphabetic letters, born on certain dates, or located at specific points on a master list.

Matching

The process of making cases and controls equivalent with respect to factors other than the exposure or factor that is being investigated

Public Health Surveillance

The process of reporting diseases which denotes "the ongoing systematic collection, analysis, interpretation, and dissemination of health data"

Active follow up

The situation in which the investigator, through direct contact with the cohort, must obtain data on subsequent incidence of the outcome

Cohort analysis

The tabulation and analysis of morbidity or mortality rates in relationship to the ages of a specific group of people (cohort) identified at a particular period of time and followed as they pass through different ages during part or all of their life span.

Volume

Using data that have numerous observations and variables

Determinants

Variables such as infectious agents, environmental exposures, and risky behaviors.

C

What data source has the advantage of being almost complete in the United States? A.Smoking prevalence statistics B. Reportable disease statistics C. Mortality statistics D. All are correct

Frequency matching

When approximately equal distributions of demographic variables such as age and gender are maintained among the cases and controls

A

Which data resource provides the best information on cancer morbidity? A. SEER B. MMWR C. NHANES D. Census Data

E

Which of the following is an example of exposure data in ecologic studies? A. per capita calorie intake B. mean ambient temperatures C. per capita income D. smoking prevalence E. all are correct

B

Which of the following is the major limitation associated with many types of cross-sectional studies? A. Ecological fallacy B. Cannot infer that the exposure preceded the development of the disease C. Lack of an appropriate comparison population

D

Which of the following is true of correlational studies comparing different communities? A. They yield results that can be applied directly to individuals B. They provide accurate measurements of exposure C. They are expensive and require a great deal of time to conduct D. They may be affected by the ecologic fallacy

A

Which of the following represents the numeric value of a relative comparison measure if the exposure prevents disease? A. 0.81 B. 1.22 C. 1.37 D. 1.05

C

Which type of comparison gives information about the strength of the relationship between the exposure and disease and is most useful for etiologic research? A. Standard comparison B. Direct standardization C. Relative comparison D. Absolute comparison

Odds ratio

a measure of the association between frequency of exposure and frequency of outcome used in case-control studies

Continuous variable

a type of variable that can have an infinite number of values within a specified range

Risk difference

difference between the incidence rate of disease in the exposed group and the incidence rate of disease in the non-exposed group