Association to Causation

Question 1

If we determined that an exposure is associated with a disease, the next question is _________________

Answer 1

whether the observed association reflects a causal relationship

Question 2

In terms of disease etiology, in the case of animal studies and in vitro systems, the results may not be applicable to humans due to ____________________ and different environmental influences across species

Answer 2

genomic difference

Question 3

True or False: Exposing humans to certain exposure is ethical

Answer 3

False, not ethical

Question 4

As exposing humans to certain exposure is not ethical what is the best alternative?

Answer 4

Make observations in human populations by:
1. Unplanned or natural experiments
2. Observed populations predisposed to disease due to certain hazards

Question 5

What are the etiological hazards for studying disease etiology?

Answer 5

1. Occupational
2. Environmental
3. Genetic

Question 6

What is the frequent sequence of studies in human populations? List them in order

Answer 6

1. Clinical observations
2. Available data
3. Case-control studies
4. Cohort studies
5. randomized Trials

Question 7

It is a part of studying disease etiology where its main goal is to review medical records and see if similar exposures are reported in other patients

Answer 7

Available Data

Question 8

Perform association studies. The quicker way to do that is to document past
exposure in diagnosed patients through a case-control study. Cohort studies may be done next to see if initially healthy individuals with the exposure develop the disease.

Answer 8

Case-control studies and Cohort Studies

Question 9

What is the quicker way to perform association studies?

Answer 9

Document past exposure in diagnosed patients through case-control studies.

Question 10

What is done next to a case-control study?

Answer 10

Cohort study

Question 11

It is ideal for beneficial or protective-against-disease exposures.

Answer 11

Randomized Control Trials (RCTs)

Question 11

Part of studying disease etiology was not done to test potentially harmful exposures

Answer 11

Randomized Trials

Question 12

In interpreting Associations we include the following:

Answer 12

1. Case-control studies
2. Cohort Studies

Question 13

What are the types of associations?

Answer 13

(1) Causal and (2) Due to Confounding

Question 14

True or False: Not knowing if an association is due to a causal relationship or not is important

Answer 14

False, Knowing

Question 15

If __________________ or ______________ preventive measures will not work

Answer 15

Causal or Due to confounder

Question 16

If cause, or there is a preventive measure against the identified exposure, disease incidence _____________

Answer 16

decrease

Question 17

It is also called as waste of resources in terms of interpreting associations

Answer 17

no/minimal change in incidence

Question 18

In direct causes of disease, what does it involve?

Answer 18

Factor, Disease

Question 19

In Indirect cause of disease, it includes:

Answer 19

Factor, Step 1, Step 2, Disease

Question 20

Necessary (-) factor disease _______ develops

Answer 20

Never

Question 21

In Sufficient (+) factor disease __________ develops

Answer 21

Always

Question 22

Give the process or diagram of Necessary and Sufficient

Answer 22

Factor A ——-> Disease

Question 23

Necessary not Sufficient

Answer 23

Factor A
+
Factor B————–> Disease
+
Factor C

Question 24

Sufficient, not necessary

Answer 24

Factor A--------------> Disease or Factor B--------------> Disease or Factor C--------------->Disease

Question 25

Not sufficient, not necessary

Answer 25

Factor A + Factor B ------> Disease or Factor C + Factor D ------> Disease or Factor E + Factor F -------> Disease

Question 26

What are the evidence for a causal relationship? Give all.

Answer 26

1. Temporal relationship 2. Strength of the Association 3. Dose-response relationship 4. Replication of the findings 5. Biologic plausibility 6. Consideration of alternate explanations 7. Cessation of exposure 8. Consistency with other knowledge 9. Specificity of the association

Question 27

It is evidence for a causal relationship, where If a factor is believed to be the cause of a disease, exposure to it must occur before the disease develops

Answer 27

Temporal Relationship

Question 28

Temporal Relationship exemplified by __________ studies

Answer 28

Cohort

Question 29

True or False: The length of interval between exposure and disease is deemed optional

Answer 29

False, exposure and disease is important

Question 30

The stronger the association, the more likely it is that the relation is ___________.

Answer 30

Causal

Question 31

The stronger the association, the more likely it is that the relation is causal.

Answer 31

Strength of the Association

Question 32

As the dose of exposure increase, risk of disease____________

Answer 32

increases

Question 33

It refers to the dose of exposure and risk of disease and no disease may develop up to a certain level of exposure above this level, and disease may develop

Answer 33

Dose-Response Relationship

Question 34

If an association is observed, we would also expect it to be seen ______________ within subgroups of the population and in different populations, unless there is a clear reason to expect different results.

Answer 34

consistently

Question 35

If an association is observed, we would also expect it to be seen consistently within subgroups of the population and in different populations, unless there is a clear reason to expect different results.

Answer 35

Replication (of the findings)

Question 36

It refers to the coherence with the current body of biologic knowledg

Answer 36

Biologic Plausibility

Question 37

Evidence for a causal relationship, where all other explanations (other possible causes) have been investigated and ruled out.

Answer 37

Consideration of Alternate Explanations (Confounding)

Question 38

Evidence for a causal relationship, if a factor is a cause of a disease

Answer 38

Cessation of Exposure

Question 39

In Cessation of Exposure as the risk of the disease decreases elimination of exposure __________

Answer 39

decreases

Question 40

Evidence for a causal relationship, if a relationship is causal, we would expect the findings to be consistent with other data.

Answer 40

Consistency with other knowledge

Question 41

Evidence for a causal relationship, where it is identified to be the weakest basis for causality (disease occurrence à multi-factorial)

Answer 41

Specificity of the Association

Question 42

An association is specific when a certain exposure is associated with only one disease.

Answer 42

Specificity of the Association

Question 43

True or False: Any observational study will be perfect

Answer 43

False, never be perfect

Question 44

In observational study there can still be ________________ in the results drawn from the collected and analyzed data

Answer 44

Credibility

Question 45

In observation studies, these are need to be taken into account:

Answer 45

1. biases 2. Confounders 3. Interactions 4. Role of chance

Question 46

it refers to any systematic error in the design, conduct or analysis of a study that results in a mistaken estimate of an exposure’s effect on the risk of disease.

Answer 46

Bias

Question 47

Selection Bias occurs where there is a ____________ _______________ between the people who are included in a study and those who are not, or when study and comparison groups are selected inappropriately or using different criteria.

Answer 47

systematic difference

Question 48

Occurs when there is a systematic difference between the people who are included in a study and those who are not, or when study and comparison groups are selected inappropriately or using different criteria.

Answer 48

Selection Bias

Question 49

Selection Bias may result from:

Answer 49

1. Disinterest among diseased or exposed individuals to join (vs volunteers) 2. Low response rates 3. Data collection is done through convenient channels (email, chat, via supervisor, etc) 4. Participant loss to follow-up

Question 50

Selection bias affects the _______________ and _______________________ regarding the association of exposure and outcome.

Answer 50

internal validity legitimacy of inference

Question 51

Control of selection bias / Assessment of the effect of bias

Answer 51

1. Use of clearly defined eligibility criteria 2. Ensure high participation rates in all study groups 3. Use external comparison 4. Conduct sensitivity analysis

Question 52

It happens when information on the exposure and disease outcome are incorrect or à Misclassification Bias

Answer 52

Information Bias

Question 53

Information bias may result from:

Answer 53

1. Limited sensitivity and specificity of diagnostic tests 2. Wrong encoding of an individual’s disease outcome and/or exposure status (Interviewer bias) 3. Enhanced recall among cases compared to control (Recall Bias) 4. Reluctance to report an exposure due to attitude, belief, and/or perception (Reporting bias)

Question 54

It is the measurement error and resulting misclassification occurs to a greater extent in one group than another

Answer 54

Differential misclassification

Question 55

HIV Cases and Sexual Exposure are stigmatized topics is an example of what type of effect?

Answer 55

underestimation of the effect

Question 56

Recall bias: Women who had a baby with a malformation tend to remember (or report) more mild infections that occurred during their pregnancies than mothers of infants without malformations. What effect does the situation above show?

Answer 56

overestimation of the effect

Question 57

It is when measurement error and any resulting misclassification occur equally among comparison groups (affects everyone in the study)

Answer 57

Non-differential misclassification

Question 58

Give ways on how to address misclassification bias

Answer 58

1. Clearly define everything that is to be measured 2. Ensure that the same instruments and methods are used in all study groups. 3. Instruments or tests need to be standardized. 4. Conduct validation (for accuracy, use of a gold standard) and repeatability (for precision) studies.

Question 59

Two types of measurement errors are?

Answer 59

Survey Analytic Study

Question 60

What are the two types of Surveys?

Answer 60

Random and Systematic

Question 61

What are the two types of Analytic Study?

Answer 61

1. Non-differential (same in all groups) 2. Differential (different in different groups)

Question 62

In a Random study, what is the consequence or outcome?

Answer 62

There is no Bias in the mean but a lack of Precision

Question 63

In terms of the systematics survey, what is the consequence of the measurement error?

Answer 63

Biased Results

Question 64

Non-differential and Differential analytic studies are either ___________ or ___________.

Answer 64

Random or Scientific

Question 65

Non-differential random or systematic could be ______________

Answer 65

Bias to Null

Question 66

Differential in Random or Systematic could be __________________________

Answer 66

Bias towards or away from the null.