assessing health risks in populations - session 12

Question 1

many diseases, or health conditions are caused by more than one _____

Answer 1

exposure

Question 2

to prevent diseases and health conditions, public health programs are directied toward ___ or ____ ___ ___

Answer 2

reducing or eliminating causal exposures

Question 3

epidemiological research focuses on: (2)

Answer 3

• identification of risk factors and risk assessment

- planning and evaluating public health interventions to reduce the incidence of disease in the population

Question 4

the knowledge created on risk and the magnitude of risk associated with various factors (_____) allows those who are responsible for protecting the public’s health to ________________

Answer 4

exposures

make decisions about allocating scarce resources (e.g. time, energy, and money), where they will have the most impact

Question 5

risk assessment helps with ___ _____

Answer 5

resource management

Question 6

for public health decision-making purposes, it is valuable to be able to answer these questions: (2)

Answer 6

• what amount of the risk of developing a disease is attributable to a particular exposure
• by what percentage would the risk of developing disease (e/g/ lung cancer) be reduced if the exposure (e.g. smoking) was eliminated? (in epi we can answer qs like this by measuring magnitude of risk

Question 7

risk assessment is a central task in ____________

Answer 7

population health research and practice

Question 8

define risk

Answer 8

risk is the probability that an event will occur

Question 9

example of risk

Answer 9

there are 100 smokers, if 60 of the smokers develop lung cancer and 40 of them do not, the probability, or risk of developing lung cancer among smokers is 60/100

Question 10

define risk factors

Answer 10

they are factors, which are statistically associated with the increased risk of a health condition (outcome)

Question 11

define protective factor

Answer 11

they are factors, which are statistically associated with the decreased risk of a heatlh condition(outcome)

Question 12

what is a measure of association

Answer 12

quantifying the strength of association between a risk factor and a health condition

Question 13

what are 5 measures of association?

Answer 13

correlation coefficient. relative risk (RR). odds ratio (OR). risk difference (RD). attributable risk (AR)

Question 14

define relative risk

Answer 14

it is the ratio of the incidence of an outcome in the presence of an exposure to the incidence of an outcome in the absence of that exposure

Question 15

the larger the RR, the ____ the ____________

Answer 15

stronger

association between exposure and outcome

Question 16

see the 2x2 table/contingency table

Answer 16

see it

Question 17

what is the formula for the incidence of disease among the exposed?

Answer 17

I1 = A/(A+B)

Question 18

what is the formula for the incidence of disease among the non-exposed?

Answer 18

I0 = C/(C+D)

Question 19

what is the formula for the relative risk?

Answer 19

RR = I1/I0

Question 20

do the exercise on page 13

Answer 20

do it

Question 21

___ is one of the central concerns of epi

Answer 21

causality

Question 22

in epi we want to be able to claim that a ____ ___ exists between a _____ ____ and a _______

Answer 22

causal association
an exposure factor
a disease (or an outcome)

Question 23

__________ must be satisfied in order to claim that a causal association exists

Answer 23

several criteria of causality

Question 24

what are austin bradford hills criteria of causality (9)?

Answer 24

1. strength of association
2. consistency
3. specificity
4. temporal relationship
5. biologival gradient
6. plausibility
7. coherence
8. experiment
9. analogy

Question 25

strong associations are less likely to be caused by ____

Answer 25

chance

Question 26

___________ between the exposure and the outcome is a required criterion for causality

Answer 26

evidence of a strong association

Question 27

describe consistency as a criteria for causality?

Answer 27

• relationships that are confirmed in mustiple studies are more likely to be causal
• look for consistent findngs: across different populations; with different study designs

Question 28

describe specificity as a criteria for causality?

Answer 28

• easier to support causation when associations are specific

- but this may not always be the case as many exposures cause multiple diseases

Question 29

describe temporal relationship as a criteria for causality?

Answer 29

• if a factor is believed to cause a disease, then it must necesssarily always precede the outcome

Question 30

describe plausibility and coherence as a criteria for causality?

Answer 30

• the observed association agrees with currently accepted understanding of pathological and biological processes
• causal mechanism must not contradict what is known about the biology of the disease

Question 31

describe biological gradient as a criteria for causality?

Answer 31

• there is evidence of a dose-response relationship

- changes in exposure are related to a trend in relative risk

Question 32

describe experiment as a criteria for causality?

Answer 32

• most often this criteria cant be met

- we cant experiment with human subjects

Question 33

describe analogy as a criteria for causality?

Answer 33

• relates to the correspondence between known associations and one that is being evaluated for causality (e.g. chemicals with similar molecular structure causing the same cancer)

Question 34

describe the web of causation

Answer 34

many factors contribute to the development of health outcomes (e.g. chronic conditions)

Question 35

give two examples of web of causation

Answer 35

1. health related behaviours (smoking, physical activity)
2. environmental influences (physical environment (e.g. air pollution), social environment (e.g. stressful social relationships))

Question 36

no single study is sufficient for ______ inference

Answer 36

causal

Question 37

why is causal inference not a simple process? (2)

Answer 37

because we need to consider the evidence and we need to be able to interpret and scientifically judge evidence