Epidemiology

Front 1

Definition of epidemiology?

Back 1

Study of the distribution & determinants of health related states or events in specified populations & the application of this study to the control of health problems.

Front 2

Frequency?

Back 2

Refers to the number of health events & the relationship of that number to the size of the population. The result allows epidemiologist to compare disease occurrence across diff. Populations

Front 3

Pattern?

Back 3

Occurrence of health-related events by time, place, & person.

Front 4

Descriptive epidemiology?

Back 4

Characterizing health events by time, place, & person.

Front 5

Determinants?

Back 5

Causes & other factors that influence the occrrence of disease & other health -related events

Front 6

Any factor (event, characteristic, or other definable entity) that brings about change in a health condition or other defined characteristic?

Back 6

Determinant

Front 7

Application?

Back 7

Applying the knowledge gained by the studies to community based practice

Front 8

What type of study is epidemiology?

Back 8

Scientific, systematic, data driven

Front 9

Spot map?

Back 9

Map showing geographic distribution of cases

Front 10

Uses for epidemiology & the information generated by epidemiologic methods?

Back 10

1. Assessing community's health
2. Making individual decisions
3. Completing the clinical picture
4. Searching for causes

Front 11

Name the 6 major tasks of epidemiology in public health practice?

Back 11

1. Public health surveillance
2. Field investigation
3. Analytic studies
4. Evaluation
5. Linkages
6. Policy development

Front 12

Public health surveillance?

Back 12

Ongoing systematic collection, analysis, interpretation, & dissemination of health data to help guide public health decision making & action

Front 13

Purpose of public health surveillance ?

Back 13

aka "information for action"
Purpose is to portray the ongoing patterns of disease occurence & disease potential so that investigation, control, & prevention measures can be applied efficiently & effectively

Front 14

Give an examples of common sources of surveillance data?

Back 14

Morbidity & mortality reports, reports from investigations of individual cases & disease clusters, health program data (immunization coverage in a community, disease registries, & health surveys.

Front 15

Purpose for field investigation?

Back 15

-Identify source/vehicle of infection that can be eliminated
-Learn more about the natural hx,clinical spectrum,descriptive epidemiology, & rask factors of disease before determining interventions.

Front 16

Definition of epidemiology?

Back 16

Study of the distribution & determinants of health related states or events in specified populations & the application of this study to the control of health problems.

Front 17

Frequency?

Back 17

Refers to the number of health events & the relationship of that number to the size of the population. The result allows epidemiologist to compare disease occurrence across diff. Populations

Front 18

Pattern?

Back 18

Occurrence of health-related events by time, place, & person.

Front 19

Descriptive epidemiology?

Back 19

Characterizing health events by time, place, & person.

Front 20

Determinants?

Back 20

Causes & other factors that influence the occrrence of disease & other health -related events

Front 21

"Shoe leather epidemiology"

Back 21

-Learn more about the natural hx,clinical spectrum, descriptive epidemiology, & rask factors of disease before determining appropriate interventions
(images of dedicated, haggard epidemiologist beating the pavement in search of additional cases & clues regarding source & mode of transmission

Front 22

Images of dedicated, haggard epidemiologist beating the pavement in search of additional cases & clues regarding source & mode of transmission

Back 22

"Shoe leather epidemiology"

Front 23

Epidemiologist must be skilled in all aspects of such studies such as?

Back 23

1.Design
2.Conduct
3.Analysis
4.Interpretation

Front 24

Design includes?

Back 24

Determining appropriate research strategy & study design, writing justifications & protocols, calculating sample sizes, deciding on criteria for subject, choosing an appropriate comparison group, & designing questionnaires.

Front 25

Conduct involves?

Back 25

Securing appropriate clearances & approvals, adhering to appropriate ethical principles, abstracting records, tracking down & interviewing subjects, collecting & handling specimens, & managing data.

Front 26

Interpretation involves?

Back 26

Putting study findings into perspective, identifying key take home message, & making recommendations.

Front 27

Analysis involves?

Back 27

-Begins w/ describing the characteristics of subj.
-Calculation of rates, creation of comparative tables, computation of measures of association, test of significance, confidence intervals ect.

Front 28

Evaluation?

Back 28

Process of determining, as systematically & objectively as possible the relevance, effectiveness, efficiency, & impact of activities w/ respect to established goals.

Front 29

Effectivness?

Back 29

Ability of a program to produce the intended or expected results in the field

Front 30

Efficacy?

Back 30

Ability to produce results under ideal condition

Front 31

Efficiency?

Back 31

Ability of program to produce intended results w/ min. expenditure of time or resources.

Front 32

Linkages?

Back 32

Epidemiology "team sport"
-Mech. for sustaining linkages: official memoranda of understanding, sharing of published or online info. for public health audiences & outside partners, & informal networking that takes place at professional meetings.

Front 33

Policy development?

Back 33

Public health epidemiologist provide input, testimony & recommendations regarding disease control strategies, reportable disease regulations, & health care policy

Front 34

Epidemiology relies on systematic approach?

Back 34

1. Counts cases or health events & describes in terms of time, place, & person
2. Divides # of cases by an appropriate denominator to calculate rates
3. Compares these rates over time or for diff. groups of people

Front 35

Case definition?

Back 35

Sets a standard criteria for classifying whether a person has a particular disease, syndrome, or other health condition.
-Consist of clinical criteria & sometimes limitations on time, place & person.

Front 36

Clinical criteria for case definition includes?

Back 36

Labs, s/s, & other

Front 37

Modifying case definitions?

Back 37

Case definitions change over time as more info is obtained.

Front 38

Criteria in case definitions?

Back 38

Case may have several sets of criteria, depending on how certain the diagnosis is.
Case may be classiied as suspected/probable.

Front 39

Variation in case definitions?

Back 39

Case definition varies according to the purpose for classifying occurrences of disease.
-ie. Sensitive & strict case definition

Front 40

Sensitive case definition ?

Back 40

"broad or loose definition" in hope of capturing most or all true cases.

Front 41

Adv. & disadv. of sensitive case definition?

Back 41

-Adv: incld. most or all true cases
-Disadv: sometimes incld. other illnesses as well.

Front 42

Strict case definition?

Back 42

Used when investigator wants to be certain that person incld. in study did have the disease.

Front 43

Disadv. of strict case definition?

Back 43

Requirement that everyone w/ symptoms be tested & an underestimation of total# of cases if some are not tested.

Front 44

Rate?

Back 44

The number of cases/size of population per unit of time.
-Useful for comparing freq. of disease in diff. locations whose populations differ in size.
-Useful for comparing disease occurrence during diff. periods of time

Front 45

The 5W"s of descriptive epidemiology?

Back 45

1.What=health issue of concern
2.Who= person
3.Where=place
4.When=time
5.Why/how=causes risk factors, modes of transmission

Front 46

Descriptive epidemiology r/t time?

Back 46

Occurrence of disease changes over time. Displaying patterns of disease occurrence by time is critical for monitoring disease occurrence in community & assessing whether public health interventions made a diff. Time data plotted on line graphs or histograms

Front 47

List 4 types of time related graphs?

Back 47

1.Secular (long term) trends
2.Seasonality
3.Day of wk & time of day
4.Epidemic period

Front 48

Secular (long-term)trends time graph?

Back 48

Graphing the annual cases or rate of a disease over a period of years.
-Used to assess prevailing direction of disease occurrence, evaluate programs or make policy decisions, infer what caused an incr. or decr. in occurrence, & use past trends as a predictor of future incidence.

Front 49

Seasonality time graph?

Back 49

Disease occurrence graphed by wk or month over the course of a year or more to show its seasonal pattern. (ie.influenza & West Nile)

Front 50

Day of wk & time of day time graph?

Back 50

Appropriate for conditions r/t occupational or environmental exposures that tend to occur at regular scheduled intervals. (ie. farm tractor fatalities)

Front 51

Epidemic period time graph?

Back 51

Shows time course of disease outbreak or epidemic.
-Use a Epidemic curve

Front 52

Epidemic curve?

Back 52

Can suggest hypotheses about time & source of exposure, mode of transmission & causative agent.
-y axis=# of cases
-x axis=time (date of s/s onset or diagnosis)
-x axis can be wks or min.
-data displayed as histogram, sometimes w/ each case displayed as a sqaure.

Front 53

Descriptive epidemiology r/t place?

Back 53

Provides insight into geographic extent of problem & geographic variation.
-Continent-street address-OR
-Urban/rural, domestic/foreign, institutional/non-institutional

Front 54

Spot map?

Back 54

Used for clusters or outbreaks w/ a limited # of cases
-a dot or "x" is placed on the location that is most relevant to disease of interest (ie.John Snow, Golden Square of London)

Front 55

Analyzing data by place?

Back 55

Can identify communities at increased risk & help generate hypotheses to test additional studies.

Front 56

Descriptive epidemiology r/t Person?

Back 56

Anaysis of data may use inherent characteristics of people(age,sex,race), biological characteristics(immune status), aquired characteristics(marital status), activities(occupation, use of meds,dx) or conditions under which they live (socioeconomic status)

Front 57

Age (person attribute)?

Back 57

-Single most important person attribute.
-Health related event vary w/ age & assoc. w/ susceptibility, opportunity for exposure, latency or incubation, & physiologic response.
-Narrow age groups to detect age related patterns. Chronic disease can use 10y age groups may be adequate.

Front 58

Sex (person attribute)?

Back 58

Males have higher rates of illness & death than do females for many diseases due to genetic, hormonal, anatomic, ect.
-Sex related diff. in the occurrence of many diseases reflect diff. in opportunity or levels of exposure

Front 59

Ethnic & racial groups (person attributes)?

Back 59

Analyzing person data by biologic, cultural, social, race, nationality, religion ect.
-Diff. in racial, ethnic, ect. may reflect diff. in susceptibility, exposure or other factors that influence risk of disease.

Front 60

Socioeconomic status (person attribute)?

Back 60

Diff. to quantify. Made up of many diff. variables(occupation, income, education,living cond.,& social standing).
-Occupation, family income, & education are most used.
status.

Front 61

Key feature of analytic epidemiology?

Back 61

Comparison group

Front 62

Experimental study?

Back 62

Investigator determines through a controlled process the exposure for each individual (clinical trial) or community (community trial) & then tracts the individual or communities over time to detect the effects of the exposure.

Front 63

Observational studies?

Back 63

Epidemiologist simply observes the exposure & disease status of each study participant

Front 64

2 most common types of observational studies?

Back 64

1. Cohort
2. Case control
3. Cross sectional

Front 65

Cohort study?

Back 65

Epidemiologist records whether each study paticipant is exposed or not & tracks participants to see if they develop the disease of interest.
-Differs from experimental b/c investigator observes rather determines participants exposure status.

Front 66

Retrospective cohort study?

Back 66

Both exposure & outcomes have already occurred

Front 67

Follow up or prospective cohort studies?

Back 67

Particpants are enrolled as the study begins & are then followed prospectively over time to identify occurrenceof the outcome of interest.

Front 68

Case control studies?

Back 68

Enroll group of people w/ disease (case pts), then enrolls group of people w/o disease(controls), then compares previous exposure b/w 2 groups.

Front 69

Cross sectional study?

Back 69

A sample of persons from population is enrolled & their exposures & health outcomes are measured simultaneously.
-Tends to assess prevalence of health outcome at that point of time w/o regard to duration.

Front 70

Epidemiologic triad/triangle?

Back 70

Traditional model for infectious disesae
1. External agent
2. Susceptible host
3. Environment that brings host & agent together
-Inadequate for diseases that have multiple contributing causes (CV disease, cancer)

Front 71

Agent?

Back 71

Infectious microorganism or pathogen.
-Agent must be present for disease to occur
-Presence of agent alone is not always sufficient to cause disease
-Can include chemical or physical causes of disease or injury

Front 72

Host?

Back 72

Human that can get the disease
-Risk factors can influence exposure, suceptibility,or response to causative agent

Front 73

Risk factors?

Back 73

Factors intrinsic to host that can influence exposure, suceptibility,or response to causative agent

Front 74

Environment?

Back 74

Extrinsic factors that affect agent & opportunity for exposure (physical, biologic, socioeconomic)

Front 75

Casual pies?

Back 75

Model for multifactorial nature of causation for non-infectious disease.
-Individual factor that contributes to cause disease is shown as a piece of pie.
-After all the pieces of pie fall into place, pie is complete & disease occurs.

Front 76

Component causes?

Back 76

Individual factors (pie pieces)

Front 77

Sufficient cause?

Back 77

Complete pie, considered casual pathway.

Front 78

Necessary cause?

Back 78

Component that appears in every pie or pathway. Without it, disease does not occur.

Front 79

Natural history & spectrum of disease?

Back 79

Progression of disease process in an individual over time in the absence of treatment.

Front 80

Incubation period?

Back 80

Stage of subclinical disease extending from time of exposure to onset of symptoms for infectious diseases

Front 81

Latency period?

Back 81

Stage of subclinical disease extending from time of exposure to onset of symptoms for chronic diseases

Front 82

Spectrum of disease?

Back 82

Disease process range from never clinically apparent illness to fatal.
Disease process will ends in recovery, disability or death.

Front 83

Infectivity?

Back 83

Proportion of exposed persons who become infected.

Front 84

Pathogenicity?

Back 84

Proportion of infected individuals who develop clinically apparent disease.

Front 85

Virulence?

Back 85

Proportion of clinically apparent cases that are severe or fatal

Front 86

Carriers?

Back 86

Persons who are infectious but have subclinical disease
-Have incubating disease or inapparent infection, or appeared to have recovered but are still infectious.

Front 87

Chain of infection?

Back 87

Agent leaves reservoir or host through a portal of exit, is conveyed by some mode of transmission, & enters through an appropriate portal of entry to infect a susceptible host.

Front 88

Reservoir?

Back 88

Habitat in which the agent normally lives, grows & multiplies.
-Humans, animals, & environment.
-May or may not be the source from which agent is transferred to host

Front 89

Human reservoirs?

Back 89

Diseases transmitted person to person w/o intermediaries
(STD, mueasle, mumps, small pox, resp. infections)

Front 90

Animal reservoirs?

Back 90

Humans are subject to disease that have animal reservoirs
-Transmitted animal to animal w/ humans as incidental host.

Front 91

Zoonosis?

Back 91

Infectious disease that is transmissible under natural conditions from vertebrate animals to humans (ie.rabies)

Front 92

Environmental reservoirs?

Back 92

Plant, soil, water.

Front 93

Portal of exit?

Back 93

Path by which pathogen leaves its host
-Usually corresponds to site where pathogen is localized

Front 94

Modes of transmission?

Back 94

Direct & Indirect
-Direct (direct contact & droplet spread)
-Indirect (airborne, vehicleborne, vectorborne)

Front 95

Direct transmission?

Back 95

Infectious agent transferred from reservoir to host by direct contact or droplet spread

Front 96

Direct contact?

Back 96

Skin to skin, kissing, sexual intercourse, contact w/ soilor vegetation harbouring disease

Front 97

Droplet spread?

Back 97

Refers to spray w/ relatively lg. short ranged aerosols produced by sneezing, coughing, or even talking.
-Classfied as direct b/c transmission is by direct spray over a few feet before droplets fall to ground

Front 98

Indirect transmission?

Back 98

Refers to transfer of an infectious agent from a reservoir to a host by suspended air particles, inanimate obj.(vehicles), or animate intermediaries(vectors)

Front 99

Airborne transmission?

Back 99

Infectious agents are carried by dust or droplet nuclei suspended in air. Includes material that has settled on surfaces & become resuspended by air currents as well as infectious particles blown from soil by wind.

Front 100

Vehicleborne transmission?

Back 100

Food, water, blood & fomites(inanimate obj may passively carry pathogen & provide environment in which agent grows.

Front 101

Vectorborne transmission?

Back 101

Mosquitoes, fleas, ticksmay carry agent or support growth or changes in agent.

Front 102

Herd immunity?

Back 102

Suggest if high enough proportion of individuals in a population are resistant to an agent, then those few who are susceptible will be protected by resistant majority.

Front 103

Endemic level?

Back 103

Amt. of particular disease that is usually present in a community. Baseline.

Front 104

Sporadic?

Back 104

Disease that occurs infrequently & irregularly

Front 105

Endemic?

Back 105

Constant presence & or usual prevalence of a disease or infectious agent in a population within a geographic area.

Front 106

Hyperendemic?

Back 106

Persistent high levels of disease

Front 107

Epidemic?

Back 107

Refers to an incr., often sudden, in a number of cases of a disease above what is normally expected in that population in that area.

Front 108

Outbreak?

Back 108

Same as epidemic but for a more limited geographic area.

Front 109

Cluster?

Back 109

Aggregation of cases grouped in place & time that are suspected to be greater than the number expected.

Front 110

Pandemic?

Back 110

Epidemic that has spread over several countries, continents, affecting lg. groups .