Epidemiology Week 13 Flashcards Preview

NSG800: Epidemiology & Biostatistics > Epidemiology Week 13 > Flashcards

Flashcards in Epidemiology Week 13 Deck (28)
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1
Q

Necessary

A

Without the factor, disease never develops

2
Q

Sufficient

A

In presence of the factor, disease always develops

3
Q

Necessary & Sufficient

A

Disease always develops in presence of the factor, but never without it. Least likely; rarely if ever happens.

4
Q

Necessary but not sufficient

A

The factor is necessary to cause the disease, but other factors are required as well. Disease will not always occur just because factor is present.

5
Q

Sufficient but not necessary

A

The factor alone can produce the disease, but it is not the only thing that can cause it; other factors also can.

6
Q

Neither necessary nor sufficient

A

No one factor working alone can cause disease, & many combinations possible. Most likely.

7
Q

Guidelines for proof of casaul relationship

A

1) Temporal relationship
2) Strength of 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

8
Q

Temporal relationship

A

Factor occurred before the disease onset.

Easier to establish in prospective cohort than case-control or retrospective

9
Q

Strength of association

A

Relative risk or odds ratio. The stronger, the more likely to be causal.

10
Q

Dose-response relationship

A

As dose of exposure increases, so does risk of disease

11
Q

Replication of findings

A

Consistent between subgroups, between studies, between populations

12
Q

Biologic plausibility

A

Coherence with current body of biologic knowledge. Some examples where clinical findings have preceded biologic knowledge.

13
Q

Consideration of alternate explanations

A

Potential confounders have been accounted for & ruled out

14
Q

Cessation of exposure

A

Risk decreases as exposure decreases

15
Q

Consistency with other knowledge

A

Findings consistent with other data (such as lung cancer rates & cigarette sales)

16
Q

Specificity of the association

A

When one disease is associated with one factor. Weakest of all guidelines.

17
Q

Selection bias

A

The way in which cases & controls are selected is not random

18
Q

Exclusion bias

A

Results from applying different criteria to cases & controls in regard to inclusion in the study

19
Q

Information bias

A

Way of gathering information among subjects is inadequate, so some of the information is incorrect

20
Q

Misclassification bias

A

Some cases are classified as controls or vice versa

21
Q

Differential misclassification

A

Rates of misclassification are different for control vs case groups

22
Q

Non-differential misclassification

A

Results from data collection methods

23
Q

Surveillance bias

A

Disease ascertainment better in the monitored population than in general population

24
Q

Recall bias

A

Potential exposure recalled by cases, forgotten by controls

25
Q

Wish bias

A

Under-reporting of exposures related to lifestyle, overemphasis of exposures related to work or environment

26
Q

Confounder

A

In a study of whether factor A causes disease B, factor X is a confounder if

1) Factor X is a known risk factor for disease B
2) Factor X is associated with factor A, but is not a result of factor A

27
Q

True or false: a confounder is an error in the study.

A

False. It is a valid finding that must be taken into account in the study of the disease.

28
Q

Interaction

A

When the incidence rate in the presence of 2 factors differs from the incidence rate we would expect to find from their individual effects