Study Designs Flashcards

(39 cards)

1
Q

What are observational studies?

A

they observe the outcomes without intervening to affect them

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2
Q

What are experimental studies?

A

the researcher manipulates the exposure (usually a drug or treatment) to compare it to the standard of care

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3
Q

What are three types of observational studies?

A
  1. Cohort
  2. Case Control
  3. Cross-sectional
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4
Q

In cohort studies, subjects are selected based on their _______.

A

exposure status

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5
Q

True or False: Cohort studies follow participants in time.

A

True

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6
Q

Two types of cohort studies: ____ and ____

A

prospective

retrospective

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7
Q

Prospective Cohort studies compare disease prevalence in the ______ and _______.

A

exposed and unexposed

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8
Q

What are retrospective cohort studies?

A

they begin with the exposure of interest and probe back for exposure information

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9
Q

What are cohort studies particularly useful for?

A

assessing RARE EXPOSURE and rapidly fatal diseases

if the exposure hurt use a cohort

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10
Q

True or False: Cohort studies can evaluate multiple diseases/outcomes from a given exposure.

A

True

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11
Q

Cohort studies can calculate ____ among exposed and unexposed.

A
INCIDENCE
#new cases during a specific time

iNcidence = New

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12
Q

True or False: Cohort studies are inefficient for rare diseases.

A

True,

inefficient for rare DISEASES but good for rare exposures

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13
Q

What are case-control studies?

A

Subjects are selected based on their disease status

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14
Q

True or False: In case-control studies, the diseased are compared to the non-diseased, which should differ only in past exposure.

A

True

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15
Q

Case-control studies can demonstrate risk ______ due to the retrospective nature of the design.

A

INDICATORS

not risk factors

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16
Q

Participants in a case-control study are chosen based on their _____ status. Therefore, at the beginning of the study, it is unknown who has been _____.

A

disease

exposed to the risk indicators

17
Q

In a case-control study, the cases and controls must have had an equal chance of _____.

A

being exposed

18
Q

Which study is best for rare EXPOSURES?

19
Q

Which study is best for rare DISEASES?

20
Q

True or False: Case-control studies can be used for diseases with a long latency period.

21
Q

True or False: Case-control studies allow for the evaluation of multiple exposures that may increase risk for disease.

22
Q

Case-control studies ____ directly compute incidence of disease in exposed/non-exposed persons. Cohort studies ____ directly compute incidence of disease in exposed/non-exposed persons.

A
Case-control= CANNOT
Cohort= CAN
23
Q

True or False: Case-control studies can establish temporal relationships.

24
Q

Case-control studies are prone to errors in _______ and ______.

A

selection of cases

collection of information

25
What are cross-sectional studies?
point in time or "snapshot" studies that do not select patients based on exposure or disease
26
True or False: Cross-sectional studies are the most basic study design.
True
27
True or False: Cross-sectional studies do not need explained etiologic objectives.
True
28
What are the study designs for experimental studies?
Randomized Clinical Trial | Community intervention Trial
29
Randomized Clinical Trials are a sub-type of _____ studies because exposure is randomly assigned by the investigator.
cohort
30
_______ is the process by which each participant's treatment is determined by an undescribed mechanism
Randomization
31
What is the primary purpose of randomization?
minimizing confounding- create groups that are not determine by any factor other than chance
32
_____ is the process by which the investigator and/or participant do not know which arm the participant is in
blinding
33
In a single-blind experiment, the ____ does not know which group the participant is in.
participant
34
In a double-blind experiment, _____ knows which group the participant is in.
neither the investigator or participant
35
What is information bias?
drawing different conclusions depending on their knowledge of which study arm a participant is in
36
What is selection bias?
study recruiters can be eager to recruit persons into the experimental arm based on their disease status
37
What are three important considerations in experimental studies?
1. stopping rules 2. sample size 3. analysis and interpretation
38
What is a systematic review?
complete summary of the literature
39
What is a meta-analysis?
combined analysis of data from different studies following strict guidelines