Brainscape's Knowledge GenomeTM

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


See full index

EBM Summer 2020 > Lecture 5 > Flashcards

Lecture 5 Flashcards

1
Q

Systematic Review

  • Overview of __ studies
  • States 4 components
A

Overview of primary studies
States objectives, materials, methods, and results. Methods are explicit, transparent, and reproducible.
Also includes a protocol.

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

Why is a systematic review better than a journalistic review?

A

A journalistic review begins with the bias of the author- they will usually include their own work. They may also use selection (publication bias) to include studies that support their position.

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

Selection (publication) bias is a similar concept to

A

Confirmation bias.

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

Cochrane review

A

Type of systematic review.

Must be unbiased, reliable, up to date, and accessible.

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

Unlike journalistic reviews, ____ are required for systematic reviews.

A

References.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Evaluating systematic reviews: What checklists are used to assess methods?

A

CONSORT for RCT
PRISMA for systematic reviews and meta analysis
Chochrane Reviewers handbook

Evaluate if methods cause bias.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Sensitivity analysis

A

Exploration of possible results of the review if designed differently. Exclude/include things to see if outcomes change.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Negative study

A

Nothing statistically significant. Not published.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

External validity assesses what?

A

If the results are generalizable to a particular population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Compare overview, systematic review, and meta analysis.

A

Big circle: Overview

Systematic review inside with meta-analysis inside that.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Meta analysis

A

Will improve power.
Subcategory of systematic review.
Statistical/numerical only.
Results of several trials which all addressed the same question.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why should you preform a meta-analysis prior to undertaking an interventional clinical trial?

A

Identifies if a question may already be answered.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does each mean on a forest plot?

  1. Green box
  2. Horizontal line width
  3. Vertical line
  4. The size of squares are proportional to
  5. Diamond
  6. Width of diamond
A
  1. Mean
  2. CI
  3. Line of no effect
  4. To the weight each trial contributes to the analysis
  5. Pooled data for subgroup.
  6. CI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Forest plot: Overlap of horizontal line for any trial of the vertical line indicates

A

There is no real difference between groups

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

Forest plot: If no horizontal lines overlap the vertical line, what does that mean?

A

Real difference between groups is 95% likely. Always accept 5% error.

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

Homogeneity

A

Result of one trial compatible with the results of others
Can Infer on forest plot if many CI are overlapping
No direct test

17
Q

Heterogeneity

A

Results of one trial are not comparable to the results of others. May be ale to infer on forest plot when there are few-no overlapping studies.
Chi square tests for heterogeneity

18
Q

Chi square test

A

Stat of heterogeneity.
Detects whether or not there is greater variation between studies than expected by random probability.
Does NOT prove homogeneity if values are below.

19
Q

DF

A

Trials - 1

20
Q

What does it mean if Chi square value is above the DF

A

Trials were different (heterogeneity) but doesn’t tell you HOW they are different.

21
Q

Inconsistency I^2

A

Assessment (not test) for heterogeneity. This converts chi square to a percentage of variability.

22
Q

Relationship between heterogeneity and inconsistency

A

More hetero = more inconsistent

23
Q

Do you want a low or high I^2 percentage?

A

Low.

0-40% is unimportant
30-60% is moderate
50-90 is substantial. Concerning.
75-100% is considerable. Shouldn’t publish. Too inconsistent.

24
Q

Does a narrow CI indicate more or less power?

A

More power. Often results from small sample sizes.

25
Q

Sensitivity Analysis

A

Results should be robust enough and not change significantly with changes in methods. Results should have external validity and be generalizable to a target population.

26
Q

Purpose of CONSORT

A

Assess quality of methods. Purpose is to improve the reporting of parallel-group RCT.

27
Q

Purpose of PRISMA

A

Assess quality of methods. Checklist of things to include in systematic reviews and meta analysis.

EBM Summer 2020 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions