Session #3

Question 1

the study of the distribution of disease and determinants of disease frequency in populations

Answer 1

epidemiology

*it is the study of the CAUSES of disease

Question 2

what is the goal of epidemiology?

Answer 2

to control health problems and imporve health at the population level

Question 3

what is operationally in reference to epidemiology?

Answer 3

• “counting” the causes of morbidity and mortality
• determining variables associated with causes of morbidity and mortality
• IDing factors that are “causes” and are POTENTIALLY MODIFIABLE
• guiding (and evaluating) interventions to improve public health

Question 4

what are the concerns of epidemiolgy?

Answer 4

that we measure both exposure and outcome accurately and understand what population is represented

Question 5

what is an endemic

Answer 5

the usual occurence of a disease in a given populaiton

Question 6

what is an epidemic?

Answer 6

a meaningful inc in the occurence of a disease in a given population

Question 7

what is a pandemic?

Answer 7

spread of a disease across a large region or worldwide

Question 8

what is the independent variable?

Answer 8

exposure of interest

Question 9

what is the dependent variable?

Answer 9

outcome of interest

Question 10

epidemiology is fundamentally concerned with what?

Answer 10

populations

Question 11

association is what?

Answer 11

an identifiable RELATION btw an exposure and a disease

Question 12

what are the 3 questions in a causal inference?

Answer 12

• methodical question (how do we look for a cause)
• ontological question (what is a cause)
• ethical question (how do we decide if there is enough evidence to act on a cause)

Question 13

what is the cause of a disease?

Answer 13

an event, condition, or characteristic that PRECEEDED the disease and without which the disease WOULD NOT have occurred at all or would not have occurred until some later time

Question 14

what is the criteria for assessing causality?

Answer 14

strength of the association
dose-response relationship
temporal sequence
biologic credibility
consistency of findinga across studies

Question 15

what is the dose-response relationship?

Answer 15

does risk inc with inc exposure?

Question 16

what does temporal sequence mean?

Answer 16

does the exposure precede the disease?

Question 17

what is biologic credibility?

Answer 17

is there a known biologic basis for the relationship?

*depends on current state of knowledge

Question 18

what is consistency of findings?

Answer 18

do multiple studies report similar findings regarding the E->D relationship?

**studies can differ by investigator, methodology, and study population

Question 19

what is the epidemiologic approach?

Answer 19

• ID a DISEASE of interest
• ID EXPOSURES of interest “risk factors”
• statistical associations btw exp./disease
• hold constant factors that may be “mixed up” in this measure of association
• infer a causal association
• recommend intervention

Question 20

what is a risk factor?

Answer 20

a factor which if present inc the probablilty of a disease occurence

• exposure must precede disease onset
• must be associated with an inc disease frequency
• absence of error and bias

Question 21

what are the 4 types of scales to quantify epidemiology?

Answer 21

• nominal scale
• ordinal scale
• interval scale
• ratio scale

Question 22

scale that uses names

Answer 22

nominal

Question 23

scale that follows an order based on severity

Answer 23

ordinal

Question 24

scale that follows a mathematical order but has no true zero

Answer 24

interval

Question 25

scale that follows a mathematical order and has a defined true zero

Answer 25

ratio

Question 26

depending on the time element we can also quantify cases as prevalent or incident by either measuring what?

Answer 26

prevalence proportion

incidence rate

Question 27

what is the prevalence proportion?

Answer 27

prevalence = #of cases/#ppl in population
at a specified time**
** is a point or period of time

Question 28

what is teh incidence rate?

Answer 28

incidence = # of NEW cases of disease/ pop at risk

over a period of time **

Question 29

prevalence/incidence is a rate?

Answer 29

only INCIDENCE is a rate and is not meaningful without a time unit

*prevalence is NOT a rate