Epidemiology Midterm 1

Front 1

John Snow

Back 1

Father of modern epidemiology. 1854 London cholera epidemic

Hint 1

Cholera

Front 2

Langmuir, Alexander

Back 2

Father of shoe leather epidemiology. Established the EIS. Contributions to disease surveillance domain.

Hint 2

EIS

Front 3

D.a. Henderson

Back 3

Initiated WHO global immunization program. Led global smallpox eradication initiative.

Hint 3

Immunization

Front 4

Janet Lane-Claypon

Back 4

Pioneer of use of cohort and case control studies.

Hint 4

Study design

Front 5

Austin Bradford-Hill

Back 5

Grandfather of modern epidemiology. Demonstrated smoking - lung cancer association. Theories of association and causation. British doctors study.

Hint 5

Lung cancer

Front 6

Model

Back 6

A hypothetical description of a complex entity or process.

Front 7

Chronic disease

Back 7

Disease characterized by a long natural history of frequent recurrence, multifactorial causation, usually a noncommunicable etiology

Front 8

Risk factor epidemiology

Back 8

Classic approach. Considers one factor at a time.

Front 9

Non-modifiable risk factors

Back 9

Inherent, genetic, individual level. Breast cancer gene

Front 10

Modifiable risk factors

Back 10

Environmental. Individual and societal level. Income.

Front 11

Multiple risk factors

Back 11

Black box model

Front 12

Modern approach to chronic disease epidemiology

Back 12

Multifactorial causation and mechanisms.

Front 13

Genetic epidemiology

Back 13

Study of the role of genetic factors and their interaction with environmental factors in the occurrence of disease in populations.

Genes considered as determinants of disease and susceptibility to the environment.

Front 14

Social production of disease frameworks

Back 14

Asserts that the primary determinant of population level disease risk (incidence) is to be found in the risk regime inhabiting a particular social address, which is a function of the material and social conditions of life.

What aspects of social structure place persons at risk for risk?

Front 15

Infectious disease model

Back 15

Specific organism -> specific disease

Front 16

Chronic disease model

Back 16

Multiple factors -> one or more diseases

Front 17

Biopsychosocial model

Back 17

Factor at multiple levels -> disease

HIV, individual behaviours and the global and national policies affecting the health of afflicted individuals.

Front 18

Association

Back 18

The observed frequency of disease varies by the level of exposure. (dose dependence)

Front 19

Causation

Back 19

An exposure caused a disease, if without that exposure disease would not have occurred.

Within a population of exposed individuals, at least some cases would not have occurred if the exposure had not taken place.

Front 20

Common cause

Back 20

A cause shared by two effects

Front 21

Common effect

Back 21

An effect caused by two or more factors

Front 22

Mediating factors

Back 22

Intermediate variable which represents a step in the causal chain connecting exposure to disease.

Front 23

Non causal associations

Back 23

Chance association and bias

Front 24

Bias

Back 24

Confounding, selection bias and information bias are examples.

Front 25

Confounding factor

Back 25

Distorts the observed effect of an exposure by mixing an extraneous factor with the actual exposure.

Criteria for a confounder :

- Causes the disease

- Associated with exposure in the source population

- Not affected by the exposure ( which would be a mediating factor)

Front 26

Sufficient cause

Back 26

Can cause the disease without the effects of any other exposure.

Example: asbestos causes mesothelioma

Front 27

Necessary cause

Back 27

Must be present in all cases of the disease. Example: HIV and AIDS

Front 28

Component cause

Back 28

Contributes to sufficient cause.

Front 29

Hill's causal criteria

Back 29

Criteria for determining causality.

Considers strength of association, consistency of association, specificity, temporality, dose -response effect, plausibility, coherence, experimental support, and analogy.

Front 30

Directed acyclic graphs (DAGs)

Back 30

Causal and temporal pathways translated into diagrams. Can never form a cycle because we can't travel back in time. Outcome and exposure of interest, as well as pre and post exposure variables.

Front 31

Population

Back 31

A group of people defined by personal traits (age, ethnicity, sex), place, and time

Front 32

Target population

Back 32

The group of individuals about whom inferences are to be made.

All young adults aged 18 years old living in BC in 2015

Front 33

Source population

Back 33

A group of individuals with the same exposure -disease relationship as the target population and who can be enumerated.

18 year olds enrolled in the BC MSP in 2015.

Front 34

Study population

Back 34

Group of individuals under observation, expected to have the same exposure - disease relationship as the source population.

Young adults graduating high school in BC who completed the survey.

Front 35

Representativeness

Back 35

How accurately the sample represents the entire population

Barriers include vague definition of target population, inability to sharply enumerate source population, issues with process for obtaining the study population from the source population (selection bias)

Front 36

Cohort

Back 36

Population of individuals moving together through time.

Front 37

At -risk

Back 37

Describes the ability of a study individual to experience an endpoint of interest.

Front 38

Person -time at risk

Back 38

Each individual in a study contributes to the total person -time at risk.

Front 39

Censored individuals

Back 39

Did not experience the endpoint of interest while under follow up. Reasons can include loss to follow up, death, or scheduled end of follow up.

Front 40

Closed cohort

Back 40

Group of at - risk individuals followed over time. All individuals enter and exit the study at the same time.

Front 41

Open cohort

Back 41

Cohort in which individuals enter and exit the study at different times.

Front 42

Rate

Back 42

Incidence rate, mortality rate

A measure of a change in one quantity per unit of another quantity.

Average rate of change.

Front 43

Proportion

Back 43

A type of ratio in which the numerator is included in the denominator.

p= a/(a+b)

Prevalence is a proportion.

May be instant or over an interval of time.

Front 44

DALY

Back 44

Disability adjusted life years. Measures the burden of disease.

DALY= YLL + YLD

Where YLL stands for years of life lost and YLD stands for years lived with disability.

Front 45

International classification of diseases (ICD)

Back 45

Numeric classification of diseases and conditions. Used for surveillance and reporting as well as insurance billing.

Front 46

Person -time at risk

Back 46

Total person -time at risk can be summed from all individuals if info is available.

Can be estimated by the area under a population decay curve or by calculating the population at mid-point multiplied by the time between enumerations (census)

Every person -moment of risk is assumed to be equal to any other person -moment of risk.

Front 47

Exposure

Back 47

Agent or substance presumed to be causal of a disease or event

Front 48

Exposure surrogate

Back 48

Factor indicating exposure potential.

Confounder?

Front 49

Intensity

Back 49

Exposure concentration at a given point in time

Front 50

Duration

Back 50

Length of time exposed

Front 51

Cumulative exposure (dose)

Back 51

Total amount of exposure = sum of all intensities X duration

Front 52

Exposure lag

Back 52

Exposure lags during some time window before the event does not have an effect