Cohort study design, Experimental study design, and Casual inference

Question 1

Group of people who share a common experience during defined time period.

Answer 1

Cohort

Question 2

Group or groups of persons are defined on the basis of presence or absence of exposure to a suspected risk factor of a disease.

Answer 2

Cohort study

Question 3

Investigator starts with group of individuals apparently free from the disease of interest.

Answer 3

Cohort study

Question 4

Proceeds from a suspected cause or etiological agent to the disease outcome.

Answer 4

General feature of cohort studies

Question 5

Follow-up studies, incidence studies, prospective studies, longitudinal studies, panel studies.

Answer 5

Cohort studies

Question 6

[2] Time relationship between initiation of study.

Answer 6

1. Conceptual sense
2. Temporal sense

Question 7

[2] Occuerrence of disease

Answer 7

1. Prospective
2. Retrospective

Question 8

Factor that plays an essential role in producing an outcome.

Answer 8

Cause

Question 9

Identifiable relationship between exposure and disease.

[association/cause]

Answer 9

Association

Question 10

Presence of mechanism that leads from exposure to disease.

[association/cause]

Answer 10

Cause

Question 11

Alteration in the frequency or quality of one event is followed by a change in the other.

[causal/non-causal]

Answer 11

Causal

Question 12

Association is a result of the relationship of both factor and disease with a third variable.

[causal/non-causal]

Answer 12

Non-causal

Question 13

Validity within the study.

[validity]

Answer 13

Internal validity

Question 14

Estimate of effect measure is accurate.

[validity]

Answer 14

Internal validity

Question 15

Not due to systematic error.

[validity]

Answer 15

Internal validity

Question 16

Validity beyond the study.

[validity]

Answer 16

External validity

Question 17

Estimate generalizable to bigger population.

[validity]

Answer 17

External validity

Question 18

Not due to random error.

[validity]

Answer 18

External validity

Question 19

Non-representative sample.

[bias]

Answer 19

Selection bias

Question 20

Inaccurate information.

[bias]

Answer 20

Information bias

Question 21

Mixing the effect of the exposure on the disease with that of a 3rd factor.

Answer 21

Confounding

Question 22

Obtain overall estimate of the association (crude: crude RR).

Answer 22

Assessing confounding

Question 23

[2] Methods to control confounding

Answer 23

1. Design stage
2. Analysis stage

Question 24

Those who are positive on the first test will be subjected to the second test.

[sequential/simultaneous]

Answer 24

Sequential

Question 25

Participants are subjected to two or more tests at the same time.

[sequential/simultaneous]

Answer 25

Simultaneous

Question 26

Subject is disease (+) when tested (+) in both tests.

Answer 26

Net sensitivity

Question 27

Subject is disease (-) when tested (-) in either test.

Answer 27

Net specificity