Epidemiology Exam 1

Incidence of a disease in a population

Degree to which a measurement or an estimate based on measurements represents the true value of the attribute that is being measured

ACE

ACHR

Rate of outcome after controlling for a variable(s) across the entire population or both groups of comparison

Subject to which an outcome is attributable (e.g. bacteria, virus, chemicals, etc)

AJE

Finding an association when one does not exist; error of rejecting a true null hypothesis;

AmJPH

Analysis of variance

APHA

Systematic failure to represent equally all classes of cases or persons supposed to be represented in a sample

# of new cases in a time period divided by population at risk in the same period } x100defined as the number of people at risk who develop a certain disease divided by the total number of people at risk

Proportion used to calculate the attributable risk (often used synonymously with attributable risk)

Amount or proportion of disease incidence that can be attributed to a specific exposure

Used to obtain the probability of disease in a group of people with some characteristic of the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals

Form of selection bias with hospital patients

Error of failing to reject a false null hypothesis; not finding an association when one actually exists

Systematic error in design, conduct or analysis of a study that results in mistaken estimate of an exposure's effect on the risk of disease

Distribution in which there are two peaks

Criterion that an observed, presumably or putatively causal association fits previously existing biological or medical knowledge

Population born during a particular period and identified by period of birth so that the characteristics can be ascertained as it enters successive time and age periodsb

Keeping the observer(s) and/or subjects ignorant  of the group to which the subjects are being assigned

Person in the population or study group identified as having the particular disease, health disorder, or condition under investigation

Study in which cases are defined as those with the disease and controls are those without the disease; can study the significance between exposure & non-exposure from the two groups (this study begins with diseased and non-diseased people...current and past)

# of deaths due to disease in time period # of ppl w/disease int hat time period          x100determines what percentage of people diagnosed as having a certain disease die within a certain time after diagnosis

Alternative to randomization  in that no comparison is made with an untreated group or with a group receiving some other treatment

Incidence in exposed    -    incidence in non-exposed

Incidence in exposed  -  incidence in non-exposed             incidence in exposed                                   x100

Incidence in population   -   incidence in non-exposed

Incidence in population   -   incidence in non-exposed                incidence in population                             x100

Data that can be separated into different categories distinguished by a nonnumeric characteristic

Factors that increase risk for an event

CCDM

CDC

Loss of subjects from a follow-up study

Disease that will last for a considerable amount of time

CIOMS

Bias due to misclassification  (ex. measurement error)

Disease characterized by signs and symptoms

Form of study that utilizes randomly assigned data in establishing sound cause-effect association(s) of agent or factor to a disease, condition or death

Set of statistical methods used to group variables or observations into strongly interrelated subgroups

Study that compares the incidence of disease between a group of exposed individuals and a group of non-exposed individuals (study begins with exposed and non-exposed individuals) - today & future

Outbreak due to exposure of a group of persons to a noxious influence that is common to the individuals in the group

Experiment in which the prevention or therapy is administered to the entire community (example fluoridation of drinking water)

Computed interval with a given probability

Computed interval with a given probability

Term used when variables or factors known to be related or associated with can influence the state of subjects being studiedthe confusion or distortion of measures of association between exposure and outcome due to a third (or more) variable(s)

A variable which is not the exposure of interest or the outcome variable that causes confounding.

Table of observed frequencies

Cox regression is a type of _________ model

Bias due to aggregation at the population level of causes and/or effects that are unlike at the individual level, occurring in ecological studies

Method of comparing two or more treatments or interventions by completing one treatment and switching to another

Method for determining which of the possible agents is likely to be the cause when confronted with several possible causal agents

Method for determining which of the possible agents is likely to be the cause when confronted with several possible causal agents

Incidence is calculated by using a period of time during which all of the individuals in the population are considered to be at risk for the outcome

Analyses are done on a post hoc basis without the benefit of prestated hypothesis; usually considered unacceptable

Difference between a true value and that obtained as a result of faulty design of a study

Bias due to systematic error in methods of ascertainment, diagnosis or verification of cases in an epidemiological study

Process of determining health status and the factors responsible for producing it

Variable in which there are only two levels or categories

One determinant is directly associated with an outcome

A relationship in which  a change in amount, intensity or duration of exposure is associated with a change in risk of a specified outcome

Bias that may occur because an association observed between variables on an aggregate level does not necessarily represent the association that exists at an individual level.

Study in which the units of analysis are populations or groups of people rather than individuals

Change of one factor alters the outcome involved

Extent to which a specific intervention, procedure, regimen or service produces a beneficial result under ideal conditions

EGRET

ELISA

EIS

Usual occurrence of a given disease within such an area

EPI

EpiInfo

Occurrence in a community or region of a group or illnesses clearly in excess of normal expectancy

Study of distribution and determinants of health-related states or events

All that is external to the individual human host

Graphic plotting for the distribution of cases by times of onset

The proportion used to calculate the attributable risk

The cause of disease

The absolute difference between the rates of disease in the entire population and the rates of disease among the non-exposed

The ability to generalize your treatment over an entire population based on the results of your sample study population

People who have the disease and who are erroneously called negative for the disease

People who do not have the disease and who are erroneously called positive by the test

# of ppl who ate the food & became ill        # of ppl who ate the food                  x100

Four parts to a scientific manuscript

Cohort study on cardiovascular disease which begun in 1948 in Massachusetts

GIS

___________ was the first to create vital statistics table

A mathematical modeling technique that allows one to analyze prospectively (Cohort studies)  collected data

Resistance of a group to a disease attack

Father of medical statistics

__________ is also known as retrospective cohort study

___________ is also known as historical study

A group from the past which is being used as a comparison group

Constant or uniform measures or variances across strata

Transmission from one person to another, directly or indirectly

Person or other living animal that provides lodgement for infectious agent under natural conditions

Study design which is a combination of more than one standard study design

ICD

Concept used that suggests that the visible or clinical cases of disease represents a small fraction of the actual prevalence

IEA

Forcing in values for missing data

Number of new cases among person time

Number of new cases of disease that occur during a specified period of time; measurement of riski

The interval from receipt of infection to the time of onset of clinical illness

First case in a family or other defined group to come to the attention of the investigator

One determinant is indirectly associated with an outcome usually with intermediate determinants

Transmission of an agent from host to susceptible by means of a vector (ex: water)

Illness due to a specific infectious agent or its toxic products that arises through transmission of that agent or its products from an infected person, animal or reservoir to a susceptible host.

A flaw in measuring exposure or outcome data that results in different quality of information between comparison groups

Voluntary consent given by a subject for participation in a study after being informed of the purpose and risks

Incidence rate of disease in the presence of two or more risk factors differ from the incidence rate expected to result form their individual effects

Systematic error due to interviewers' subconscious or conscious gathering of selective data

IRB

JAMA

Pioneered studies in vaccination.

Measure of the degree of nonrandom agreement between observers of the same categorical variable

List of postulates that should be met before causative relationship can be accepted

Infection with no active multiplication of the agent; only genetic message present in the host, not the viable organism

Overestimation of survival time due to backward shift of starting point

Systematic error due to selection of disproportionate numbers of long-duration cases in one group but not another

Summarizing technique used to describe the pattern of mortality and survival in populations

Conducted one of the first randomized trials on scurvy by administering lemons randomly to the crew

Statistical analysis which determines an individual's risk of the outcome as a function of a risk factor; outcome of interest has two categories

Study in which the exposure and non-exposure groups are ascertained. Groups are then followed up for several years into the future and incidence is measured

Study subject(s) who cannot or do not complete participation in a study for whatever reason

Allows a summary of multiple findings/stratum/relationships. an odds ratio that summarizes a number of odds ratios from a group of stratified contingency tables.

Analysis in which the study group and the control group are comparable with respect to extraneous factors

Systematic error from inaccurate measurements of subjects on study variables

Statistical analysis of a large collection of analyses resulting from individual studies for the purpose of integrating the findings

Dirty air makes people sick

Bias that occurs when a person is classified into the wrong category

MMWR

They way a infectious agent is transmitted

Departure from a state of mind or body well being

Resulting in death

Total # of deaths from a specified causetotal population at midpoint of specific time period    x100

MRFIT

Statistical analysis which uses more than on variable

Systematic difference between a true value and that actually observed, due to observer variation

Probability that event will occurprobability that even will not occur

(a/b)     =   (ad) (c/d)          (bc)        OR

Data that may be arranged in order but values can't be determined or meaningless

Epidemic limited or localized increase in incidence

Research on outcomes of interventions usually used to describe the results of treatment in clinical or surgical setting

Extreme data values that may be correct but may disguise the true nature of the distribution when illustrated though histogram. (Dr. Yu says this)

When groups are match too elaborately, can mess up evidence

PAHO

Worldwide epidemic

Immunity you get from antibody produced by another host and acquired naturally by infant from mom or artificially.

Mechanism by which etiologic agent produces disease

A measure of how many individuals  were affected with disease during a specified time period

Infection that persists for years and sometimes life

Sum of individual units of time that persons in the study population have been exposed to condition of interest.

Clinical pharmacologic studies of 20-80 patients that look at pharmacologic and toxic effects

Each event or variable is independent from one another.

NCHS

Proportion of patients who test negative that do not have disease

Hybrid study design in which a case-control study is nested in a cohort study

NHANES

NIH

May include preclinical, subclinical, persistent (chronic), and latent disease

Issue sometimes found during studies where patients either drop out of study or may stop taking agent and not admit it to researcher

________________________________ same as retrospective cohort study

Hospital acquired infection

Statistical hypothesis that one variable has no association with another; or two or more population distributions do not differ from one another

Clinical investigations of 100-200 patients for effectiveness and relative safety

Large-scale randomized controlled trials for effectiveness and relative safety, which often multi-centered

Postmarketing surveillance that is important for monitoring new agents as they come into general use by the public

Inert substance

Prevalence of disease at point in time

Proportion of patients who test positive that actually have the disease in question

1 - BThe ability of a study to demonstrate an association if one exists

Disease that is not yet clinically apparent, but will eventually progress to clinical disease

Precision + validity = ___________

Reduction of random error; lack of random error

Ability of measurement tool to distinguish between who has the disease and who does not

Incidence  x Duration of disease = ________# of affected persons present in the population at a specific time    x100            # of persons in the population at that time

Person who introduces the disease

Action taken to prevent the development of a disease in a person who is well and does not have the disease in question (condom use, vaccine)

When sign and symptoms of disease first appear

Probable or likely projection of the course in which the disease will travel from the time of diagnosis to either the termination of the disease or death

Epidemic that progresses though a community or population; not from a single source

Tendency for publications to report positive findings and  not publish  articles that do not yield significant results

Method for sampling people in telephone surveys in which telephone numbers are randomly dialed

Unpredictable assignment of subjects

Form of study design (trial) where a defined population is split into two groups:1) those that will receive the new tx2) those that will receive the current txthen, comparison will be done on who improved & who didn't between the 2 groups

Measure of frequency of occurence

Value obtained by dividing one quantity by another

Systematic error due to differences in accuracy or completeness of recall to memory of past events or experiences

Systematic error due to the differences in accuracy or completeness of recall to memory of past events or experiences

Systematic error due to the inconsistent recruitment of subjects based on the identification of subjects by clinicians and other study subjects

Incidence rate of disease w/exposureincidence rate of disease w/o exposure

The ratio of risk (incidence) between two populations, groups or exposure categories

Degree of stability exhibited when a measurement is repeated under identical conditions

Selective revealing or suppression of information about past medical histroy

Systematic error due to differences in characteristics between those that choose or volunteer to take part in a study and those who do not.

# of completed or returned surveys divided by the total # of persons who would have been surveyed if all had partcipated

Follow a cohort from some point in the past to a predetermined stopping point. investigator can then compare the significance of who acquired the disease and who did not from the exposed and non-exposed

Probability that event will occur

Process of determining risks to health attributable to environmental or other hazards

Factors that increase a person's risk for a disease

A selected subset of a population

Systematic error due to study of a nonrandom sample of a population

Complete list of individual entities to be sampled from

Individual entity that makes up the study sample

Commonly used statistical software program

# of exposed to primary case with diseease     total # of exposed to primary case             x100

The identification of people who have already developed a disease, at an early stage in the disease's natural history (screening and early intervention)

The way in which cases and controls, or exposed and non-exposed people were selected in such a way that an apparent association is observed even if, in reality exposure and disease are not associated. Apparent association is called __________________

Ability of a test to identify correctly those who have the disease              TP                            TP  + FN

The ability of a test to identify correctly those who do not have the disease               TN                               TN + FP

Condition that can be used to assess the stability or change in health levels of a population by monitoring mortality stats

SER

Visible indications that help confirm diagnosis of a disease (ex: rash)

SMR

SMSA

Cholera in London, England: attributed disease to contaminated water. Solved historical epidemiological investigation.

True negative

SPSS

Observed # of deaths per yearexpected # of deaths per year

Analyzing data where the sample is separated into several subsamples according to specified criteria such as age groups, socioeconomic status, etc

Magnitude of the measure of association

Disease that is not clinically apparent and not destined to become clinically apparent.

Ascertainment is considerably better with a closely monitored population. May lead to an erroneous estimate of the relative risk or odds ratio

Time of identification of an outcome to death is __________ time

Degree at which a person is at risk for certain disease or outcome

Indicators, not necessarily visible. Help confirm diagnosis of disease or outcome

Combined effect is greater than solitary effects

Limiting disability after disease already occured

The amount of time from subject identificaiton to the occurrence of the outcome

Time from identification of an outcome to death

A type of contingency table

Type I error; occurs when one concludes that treatments are different when in reality they're not

Type II error; occurs when one concludes that treatments are not different when in reality they are

Chronic carrier of salmonella typhi

Disease or injury which initiated the train of morbid events leading directly or indirectly to death or the circumstances of the accident or violence which produced the final injury

Distribution with one peak

Statistical analysis which uses one independent variable

The ability of a test to distinguish between who has disease and who does not

Something that transports an infectious agent from an infected individual or its waste to a susceptible individual

Denotes transmission from one generation to another; primarily genetic transmission

Degree of pathogenecity

Certificates of birth, death, marriage, and divorce

Systematic error attributed to differences in the reasons why people volunteer for a study

Current theory explaining causation

WHO

Recognizes that death occurring in the person at a younger age clearly involves a greater loss of future productive years than were it to occur at an older age

Infection or infectious disease transmissible under normal conditions from vertebrate animals to humans

How you collect data

Current & past; no incidence measurement = 0 risk (aka retrospective)