Epidemiology and Causation

Question 1

What is epidemiology?

Answer 1

the study of distribution and determinants of health-related states or events in a specific population and the application of the study to control and avoid health problems.

Question 2

what is cause?

Answer 2

something that either alone or in combination with other factors produced an outcome.

Question 3

what is a sufficient factor?

Answer 3

the presence of this factor alone is enough to result in disease

Question 4

what is a necessary factor?

Answer 4

the disease never presents if this factor is absent

Question 5

what are pre-disposing risk factors?

Answer 5

age, sex, genetic traits, etc.

Question 6

what are enabling risk factors?

Answer 6

factors that help the disease begin and progress

Question 7

what are disabling risk factors?

Answer 7

factors that hinder or slow recovery

Question 8

what are precipitating risk factors?

Answer 8

exposure to the disease agent

Question 9

reinforcing risk factors?

Answer 9

repeated exposure, environmental conditions that promote disease development. stress

Question 10

what are risk factors?

Answer 10

situations that increase the likelihood/rate of disease development

Question 11

what are protective factors?

Answer 11

factors that reduce disease development

Question 12

what are attributable factors?

Answer 12

a quantifiable measure for the preventative impact of elimination a specific causal factor

Question 13

bradford-hill criteria?

Answer 13

• temporal relationship
• plausability
• consistency
• strength of association
• dose response
• reversibility
• strength of study design

Question 14

what is temporal relationship?

Answer 14

exposure occurs before disease.

Question 15

what is needed for a factor to be labelled as a cause?

Answer 15

temporal relationship

Question 16

what is plausibility?

Answer 16

consistent with other knowledge and studies conducted

Question 17

what is consistency?

Answer 17

studies conducted in other places and with different populations show the same findings

Question 18

what is strength of association?

Answer 18

the higher the relative risk, the more likely it is to be a “cause”

Question 19

what is dose-response?

Answer 19

possible correlation between increasing exposure and severity of outcome or disease

Question 20

what is reversibility?

Answer 20

dose removing the exposure remove/improve the state of the disease

Question 21

what is strength of study design?

Answer 21

the type of study determines the strength of the research

Question 22

what 3 things must we consider for determining cause-effect relationship?

Answer 22

bias, confounding, chance

Question 23

what is bias?

Answer 23

errors of a study that make the data less reliable

Question 24

what type of errors come under bias?

Answer 24

• random errors

- systemic errors

Question 25

what are random errors?

Answer 25

errors that are caused by various factors

Question 26

examples of random errors?

Answer 26

biological variation, sampling error, measurement error

Question 27

how to get rid of random error?

Answer 27

generally eliminated by averaging

Question 28

what are systemic errors?

Answer 28

errors that result in non-zero mean?

Question 29

what are examples of systemic errors?

Answer 29

- selection bias - measurement bias - recall bias

Question 30

what is selection bias?

Answer 30

when the cohort is not properly randomized

Question 31

what is measurement bias?

Answer 31

poor/inaccurate measuring

Question 32

what is recall bias?

Answer 32

mental state affecting the participants responses

Question 33

what is confounding?

Answer 33

extraneous variables that can alter assessment of a cause-effect relationship

Question 34

3 factors for confounding?

Answer 34

- must be a risk factor for disease among those who are not exposed to the factor of interest - must be associated with the exposure of interest 9in the source population) - must not be an intermediate between exposure and the outcome (must not lie on the causal pathway)