Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Epidemiology > Cohort Studies > Flashcards

Cohort Studies Flashcards

1
Q

What are cohort studies?

A
  • Observational studies allowing the researcher to passively observe natural events occurring in naturally exposed and unexposed (comparison) groups.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two versions of a cohort study?

A
  • Group-allocation based on exposure status

- Group membership because of something in common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are some other names for cohort studies?

A
  • Incidence studies
  • Follow-up studies
  • Longitudinal studies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is commonly generated from cohort studies?

A

Risk of disease/outcome.

Risk Ratio/Relative Risk (RR) as a measure of association

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are some reasons for selecting a cohort study?

A
  • Unable to force group allocation
  • Limited resources
  • The exposure of interest is rare in occurrence and little is known about its associations/outcomes (v1)
  • More interested in incidence rates or risks for outcome interest (more than effects of interventions)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 fashions/perspectives that a cohort study can be conducted in?

A
  • Prospective
  • Retrospective
  • Ambidirectional
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Prospective Cohort Studies

A
  • Exposure group is selected on the basis of a past or current exposure and both groups followed into future to assess for outcomes of interest and then compared
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Retrospective (Historical) Cohort Studies

A
  • At the start of the study both exposure and outcome of interest have already occurred, but groups allocated based on past history of exposure.
  • Retrospectively start at time of exposure and follow forward to the point of outcome occurrence (known) in the present
  • exposure still has to happen before outcome of interest and group allocation is based on exposure status
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ambidirectional Cohort Studies

A
  • Uses retrospective design to assess past differences (up to present, but adds future data collected on additional outcomes prospectively from start of study.
  • looking for outcomes in the past and into the future
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the types of cohorts that refer to a group with something in common?

A
  • Birth Cohort
  • Inception Cohort
  • Exposure Cohort
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Birth Cohort

A
  • Individuals assembled based on being born in a geographic region in a given period of time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Inception Cohort

A
  • Individuals assembled at a given point based on some common factor
  • Where people live, work, or something they have in common
  • Useful for single-group assessments for incidence rate determination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Exposure Cohort

A
  • Individuals assembled based on some common exposure

- frequency connected to environmental or other one-time events

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Fixed Cohort

A

A cohort which can’t gain members but can have loss-to-follow-ups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Closed Cohort

A

A fixed cohort with no loss-to-follow-ups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Open (or Dynamic) Cohort

A
  • Cohort with new additions and some loss-to-follow-ups

- Can increase or decrease over time, as people emigrate or immigrate in and out of cohort (population) being studied

17
Q

How do you select an unexposed study population?

A

Make the groups as close as possible

18
Q

What 3 sources can the unexposed group come from?

A
  • Internal
  • General Population
  • Comparison Cohort
19
Q

Internal Source

A

Patients from the same cohort, who are unexposed

  • best, if feasible
20
Q

General Population Group

A
  • used as a second choice when the internal is not realistically possible

(E.g. Everyone is exposed)

21
Q

Comparison Cohort

A
  • Least acceptable group

- simply attempt to match groups as close as possible on numerous personal characteristics

22
Q

What are the strengths of cohort study designs?

A
  • good for assessing multiple outcomes of one exposure
  • Useful when exposure are rare
  • Useful in calculating Risks and RR
  • Less expensive than interventional
  • Good when ethical issue limit use of interventional
  • Good for long Induction/Latent periods (retro)
  • Able to represent temporality (Pro)
23
Q

What are some advantages of Prospective Cohort Studies?

A
  • Can obtain a greater amount of study-important information from patients
  • Follow up or tracking patients may be easier
  • Better at giving answer to temporality
  • May look at multiple outcomes from a (supposed) single exposure
  • Can calculate incidence & incidence rates
24
Q

Disadvantages of Prospective Cohort Studies

A
  • Time, Expense, & Lost-to-follow-up
  • Not efficient for rare diseases
  • Not suited for long induction/latency conditions
  • Exposure may change over time
25
Q

Advantages of Retrospective Cohort Studies

A
  • Best for long induction/latency conditions
  • Able to study rare exposures
  • Useful if the data already exists
  • Saves time and money compared to prospective
26
Q

Disadvantages of Retrospective

A
  • Requires access to charts, databases, employment records
  • information may not factor in or control for exposures to harmful elements during study period or over time
  • patients may not be available for interview if contact necessary for missing or incomplete data
  • Exposure may be changed over time
27
Q

Matching

A

A way to make groups as equal as possible on known/potential confounders

28
Q

Key biases with cohort studies

A
  • Healthy worker effect

- Selection bias

Epidemiology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions