Epidemiology Midterm

Front 1

What is the definition of Epidemiology?

Back 1

Study of the distribution and determinants of health-related states or events in specified populations (and application of this study to the control of health problems)

Front 2

What were the 4 major historical time periods in epidemiology?

Back 2

Sanitary Era, Infectious Disease Era, Chronic Disease (Modern Era), New Era

Front 3

What was important in the Sanitary era of Epidemiology?

Back 3

keeping of vital records, sanitation, Snow, Semmelweiss

Front 4

What was important in the Infectious Disease era of Epidemiology?

Back 4

germ theory of disease, Koch, Pasteur, Nightingale

Front 5

What was important in the Chronic Disease era of Epidemiology?

Back 5

Focus back on individual risk factors , chronic diseases - smoking and lung cancer Doll and Hill, Framingham

Front 6

What was important in the Current era of Epidemiology?

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Infectious disease epi back, some as chronic consequences, individualized risk, gene interaction and risk

Front 7

Hippocrates

Back 7

first people to provide a rational disease explanation, endemic vs. epidemic, first to look at disease in population

Front 8

John Graunt and Farr

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Systematically looked at death records and analyzed

Front 9

James Lind

Back 9

Scurvy - first recorded experimental studies - controlled conditions for all participants

Front 10

Edward Jenner

Back 10

First to notice that those who had cowpox could not get smallpox

Front 11

Pierre Charles Luis

Back 11

father of epidemiology - first real systematic numerical analysis of study - biostatistics - taught many future important figures

Front 12

William Farr

Back 12

classification of disease - standardized statistical methods - large sample size - multi-factorial etiology

Front 13

Ignaz Semmelweis

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maternal mortality study - start of germ theory - ideas rejected because of entrenched beliefs.
provided consistent evidence in different populations

Front 14

John Snow

Back 14

broad St. pump investigation, mapping theory, brought about immediate change, used a control group

Front 15

Robert Koch

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1 to 1 correlation between microorganism and disease - germ theory

Front 16

Joseph Goldberger

Back 16

demonstrated that illness could be caused by factors other than microorganisms

Front 17

what is the disease iceberg concept?

Back 17

When the disease we see or that are reported are grossly underestimating the actual occurence because of the disease characteristics. This is beause most people w/ disease do not seek medical assistance, only most severe cases are seen by the doctors.

Front 18

what are the components of the epidemiological triangle of disease?

Back 18

agent, host, environment, and sometimes vector

Front 19

infectivity refers to

Back 19

the spread of disease

Front 20

pathogenicity refers to

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how many will get apparent disease

Front 21

virulence refers to

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the severity of disease

Front 22

toxigenicity refers to

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the ability of the agent to produce toxins

Front 23

resistence refers to

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the ability of the agent to withstand environmental changes

Front 24

antigenicity refers to

Back 24

whether the agent produces an immune response in the host

Front 25

the chain of infection refers to

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reservoir, portal of exit, transmission, portal of entry, susceptible host

Front 26

timeline of disease includes

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disease free, induction, latency, diagnosis and treatment and convalescence

Front 27

natural history of disease includes

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susceptibility, presymptomatic, clinical disease and stage of diminished capacity

Front 28

what is the difference between primary, secondary and tertiary prevention?

Back 28

primary - before disease, secondary - early detection and treatment, tertiary - mitigating affects of disease

Front 29

what is an independent variable

Back 29

variable that affects the outcome (predictor)

Front 30

what is a dependent variable

Back 30

variable that IS the outcome

Front 31

where are inferences made in study design?

Back 31

internal validity, (actual sample to intended sample) includes things like loss to follow-up and bias.

Front 32

Incidence Rate

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# new cases/ person-time

Front 33

cumulative incidence

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# of new cases during specific time period/ population at risk at beginning of time period

Front 34

Point Prevalence

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# of existing cases at specific point in time/ total population at specific point in time

Front 35

Period Prevalence

Back 35

# of existing cases during specific time period/ total population during specific time period

Front 36

Incidence Odds

Back 36

# who developed disease during time period/ # who did NOT develop disease during time period

Front 37

Prevalence Odds

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# who had disease during time period/ # who did NOT have disease during time period

Front 38

What is external validity #1?

Back 38

inferences made from the sample population to the accessible population

Front 39

What is external validity #2?

Back 39

inferences made from the accessible population to the intended population usually qualitative

Front 40

What are the 2 major types of measurement levels?

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Continuous and Categorical

Front 41

Categorical measurements can be classified as what types?

Back 41

Nominal (non-ordered list of categories), Ordinal (an ordered list of options), Dichotomous (2 choices)

Front 42

Crude Death Rate

Back 42

deaths during specific time period/ entire population at specific time period

Front 43

Crude Birth Rate

Back 43

births during specific time period/ entire population at specific time period

Front 44

Proportionate Mortality Ratio (PMR)

Back 44

# of deaths due to specific cause/ total # of deaths in the population

Front 45

Cause-Specific Mortality Rate

Back 45

# of deaths due to specific cause/ entire population at midpoint of time period

Front 46

Case Fatality Rate

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# of deaths due to specific disease/ # of cases of disease during same time period

Front 47

Survival Rate

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# newly diagnosed patients with disease - # of deaths among patients with disease/ # newly diagnosed patients with disease

Front 48

Years of Potential Life Lost (YPLL)

Back 48

measure of importance of premature death.
Weighted towards death at younger ages.

Front 49

Fertility Rate

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# of live births/ # of women aged 15-44

Front 50

Risk Ratio/Relative Risk

Back 50

[a/(a+b) / c/(c+d)]

*for cumulative incidence and prevalence

Front 51

Rate Ratio

Back 51

[a/(person-time among exposed) / c/(person-time among unexposed)]

*for incidence rate

Front 52

Study designs can be classified into 2 major categories...

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experimental and observational

Front 53

Experimental studies include what study type?

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randomized control trials

Front 54

Observational studies can be classified as either ___ or ____

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descriptive or analytical

Front 55

What constitutes a randomized control trial?

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researcher sets the exposure (or lack of exposure) in an individual or group

Front 56

the 2 types of randomized control trials (not group and individual)

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therapeutic or preventative

Front 57

Odds Ratio

Back 57

ad/bc

used for case control studies

*for incidence OR, prevalence OR and exposure OR

Front 58

Attributable Risk

Back 58

[a/(a+b) - c/(c+d)]

*Rate in exposed - rate in unexposed

Front 59

Percent Attributable Risk

Back 59

(RR - 1)/RR x 100

Front 60

Population Attributable Risk

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Rate in the population - Rate in the unexposed

Front 61

Percent Population Attributable Risk

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(Rate in exposed x (RR - 1)) / (Rate in exposed x (RR - 1) + 1) x 100

*usually rate in exposed is given in question.

Front 62

What study types are descriptive studies?

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case series, descriptive, and sometimes cross sectional and ecological

Front 63

What study types are analytic studies?

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case-control, cohort, and sometimes cross sectional and ecological

Front 64

What are characteristics of a cohort study?

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group of people with similar characteristics in whom exposures are known initially and explores disease occurrence.

Front 65

What are the characteristics of a case-control study?

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focuses on people with or without the outcome and then explores possible exposures (exposure and outcome already occured)

Front 66

What are the characteristics of a cross sectional study?

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snapshot in time, assesses exposures and outcomes at a single time point

Front 67

What are the characteristics of an ecological study?

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describes rates of occurrence at the population level

Front 68

Herd immunity

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resistance of a group/population to the spread of a disease due to a high enough proportion of immune people.