Systematic Review/ Meta Analysis
Process of A SR: Step 6-7 How will authors sometimes weigh the material
based on the average estimate of the effect, makes it so bad articles do not impact the results as much
How do qualitative analysis (SR) determine the words?
based on the count and quality of the articles
Review articles are typically
biased
Why are inconclusive findings useful?
clinical often misled by the results of one study that agrees with their philosophy -they search for an article they agree with and it might just be an atypical result for an intervention
Where can you find the least bias and most expensive SR/MA?
cochrane collaboration
Process of A SR: Step 1 Cochrane and other systematic reviews often compare the intervention to several "________" conditions
comparison
Process of A SR: Step 1 PICO become what for a SA (3)
inclusion criteria exclusion criteria search terms
Common SR results 1. What findings are common?
inconclusive findings
How is a SR unbias?
it includes ALL articles
Process of A SR: Step 5 How does the systematic review become bias when you only use articles that only include ONE outcome measure
just because the study doesn't use the same outcome/units doesn't mean the study is worse. SR become bias because the conclusion of it might not be true.
Process of A SR: Step 2 and 3 Define the _______ ______
literature search (search terms)
What is expert opinion?
lowest quality clinical experience, guidelines, review articles
What is it called when it is approtiate to combine the results from different studies and settings?
meta analysis
results are represented statically
meta analysis
Systematic Review -What about the quality of articles used in a systematic review?
quality of individual articles is extensively analysis -you know if they are using low quality articles. low quality would be consider a 2A not 1a because the quality of articles is low.
Process of A SR: Step 6-7 1. Scales are used to score the
quality of the studies (internal validity)
Process of A SR: Step 6-7 Must review articles for
quality/ internal validity
Dimensionless measures nominal or ordinal outcome measures
relative risk or odds ratio
Review Articles- Traditional Approach lack of description of the organized approach to gathering....
relevant literature data
Process of A SR: Step 4 Avoidance of selective ________ bias
reporting
Process of A SR: Step 5 After searching the articles the author will
retrieve/ screen articles
Process of A SR: Step 6-7 Use a scale to
review each article
An inconclusive result or negative SR may cause a PT to
review their practice patterns -start question why they are using their methods
Heterogeneity in studies happens because (2)
sample characteristics- inclusion/exclusion, baseline function/disability methodology- length of follow up, handling of data
authors choosing not to include certain RCT results for publication
selective reporting
Heterogeneity in studies
show significant differences between studies
Process of A SR: Step 5 How can outcome be very specific in a SR?
some require a consistent outcome measure for all studies example cannot compare seconds to inches
Dimensionless measures interval or ratio outcome measures
standard mean difference weight mean difference
Process of A SR: Step 1 The comparison conditions include
standard of care no care competing interventions (multiple comparisons: education, treatment, no treatment)
Process of A SR: Step 6-7 Scaling is sometimes used to? Example
statistically place more emphasis on results of high quality studies example pedro and JADAD
What words do qualitative analysis (SR) use
strong, moderate, minimal evidence for/ against treatment
What is the one problems with synthesizing findings?
studies often use different outcome measures to quantity the same construct
Process of A SR: Step 8-9 What are you doing here?
synthesize/analyze the findings
Qualitative analysis=
systematic review
describes the results results will be in words "we had three articles that showed a positive effect"
systematic review
Process of A SR: Step 5 Some of the articles will not meet
the predetermine criteria
What typically determines if the study results will be synthesize statistically?
the study's heterogeneity- probably will be a SR if it has a lot of heterogeneity
What is the goal of a SR?
to synthesize results of all relevant studies that evaluate a common question to get an answer
What is the solution with different outcome measures?
transform results of each study into a dimensionless measure (SMD or WMD)
When do some authors not do Cochran Q or Chi Square test when determining heterogeneity?
when there are few studies (less than 5)
When does the author decide if it should be a SR or MA?
at the end and by looking at the data
Process of A SR: Step 4 As a reader how can you find out what authors are not reporting?
authors who are funded must publish a protocol of their study. the protocol tells what they were funded for. so all the information they were saying the were going to do.
Meta analysis improves external validity by?
pooling results from across settings (acute, day rehab, SNF)
a bunch of low quality RCT=
poor systematic review
To avoid publication bias what can you do?
"Grey literature" search for articles that haven't been published
Narrative Review - ______ or _____ topic -No _______ ________ required of studies included in review - There is no reason to include...... -Was is not reported? - Do not know how? -_______ and or level of ______ of studies included in review
- GENERAL or FOCUSED topic -No SPECIFIC CRITERIA required of studies included in review - There is no reason to include ARTICLES THAT DO NOT AGREE WITH YOU -Was is not reported.. SEARCH AND SELECTION METHODS - Do not know how? THEY GOT THE ARTICLES - QUALITY and or level of EVIDENCE of studies included in review
Review Articles- Traditional Approach -_______ review - ______ opinion -_____ statement -________ review statements
- UNSYSTEMATIC review - EXPERT opinion - CONSENSUS statement -NARRATIVE review statement
The specific search and selection methods with a systematic review -tells you what search terms were used to... -would allow you to.....
- find the articles -reproduce the search
Systematic Review - focused _____ (____) -Summary of findings from studies that meet _______ ______
- focused QUESTION (PICO) it will be very specific, patient outcome and intervention -Summary of findings from studies that meet SPECIFIC CRITERIA every article meets the criteria associated with PICO
Review Articles do not tell you how they gathered relevant literature data - there is no ____ or ____ criteria to evaluate -they might only pick articles based on their _______
- there is no INCLUSION or EXCLUSION criteria to evaluate -they might only pick articles based on their OPINION, only support their opinion.
Process of A SR: Step 6-7 1. Each article is typically review by at least _____ reviewers 2. This is to? 3. What may the reviewer do? 4. How are discrepancies between raters settled?
1. 2 2. Avoids one person opinion 3. Reach out to the author for clarification 4. By a 3rd reviewer
Process of A SR: Step 1 What are the 5 categories and the studies that would be used that the QUESTION/PICO fits into
1. diagnosis: cross sectional study 2. etiology 3. prognosis: cohort study or epidemiology 4. treatment/intervention: RCT 5.prevention
What are 5 advantages of a MA
1. increase power 2. more precise estimate of the effect (larger n) 3. quantifies the magnitude of the effect - moderate, small... 4. resolves conflicting results 5. may improve external validity
Process of A SR: Step 2 and 3 1. Define the _______ 2. Positive of being broad 3. Negative of being broad example exercise might be
1. intervention 2. lots of articles for review 3. no as specific example cardio, strength training
What are two ways systematic reviews are helpful?
1. it is imposisble to stay current with all the new research -SR help you filter out the bad articles and find the good articles 2. SR reduces the tendency to read articles that "agree" with you or that you are "looking for"
Process of A SR: Step 6-7 The scales are based off of what three things
1. methodology/ randomization 2. masking/blinding 3. reporting and treatment of missing data
Process of A SR: Step 2 and 3 1. What will the ________ population look like. 2. Consider: Will it apply to my ______
1. patient 2. setting
Process of A SR: Step 4 A comprehensive, objective, literature search 1. The data search must be _____ with (3) 2. The author must provide
1. reproduceable- phases, terms, limits 2. The date of the data search
Process of A SR: Step 2 and 3 Determining the Search Terms 1. What type of _____ are going to be included
1. studies
What are the two ways information can be synthesized?
1. systematic review 2. meta analysis
Not all SR are a
MA
What way do we evaluate SR/MA?
PRISMA
Systematic Review -Rigorous ______ and _____ methods establish prior
SEARCH and SELECTION
All MA are a
SR
What does the cochrane collaboration do?
SR/MA across health care
Meta analysis is a subgroup of
a systematic review
How does a SR reduces the tendency to read articles that "agree" with you or that you are "looking for"
an SR aim is to come out with a conclusion on a topic in an unbiased way
Process of A SR: Step 6-7 What is the purpose of scaling the quality of articles?
assure the readers the "garbage in/ garbage out" does not apply
What are three ways to search for grey literature?
contact authors for unpublished data government studies dissertation/thesis (university libraries)
Process of A SR: Step 4 A comprehensive, objective, literature search 1. What must be provided?
databases and search terms
What are two ways you can tell the Heterogeneity in a study?
degree of overlap of study confideince intervals cochran q or chi square tests
It is important to determine why Heterogeneity between the studies exist
design type, length of follow up, the way data is collected, population studied
Process of A SR: Step 10 A flow chart reporting
detailed explanation of studies and outcomes included in the results - how you found the studies (pubmed, gray search) -why articles were not included (allows the reader to determine if the author was bias)
Process of A SR: Step 4 This is when you
do a comprehensive, objective, literature search
Process of A SR: Step 5 What are the cons of using only one outcome between studies?
excludes findings from RCT that may affect the validity of the reviews conclusions
Process of A SR: Step 5 What are the pros of using only one outcome between studies?
facilitates homogeneity of the results and combing results between studies
What two CEBM reccomendations should you not use with a SR
foundational evidence expert opinion
Systematic review does NOT
give the magnitude, just provides the number of studies that agree
Consensus
group of people providing their opinion
Heterogeneity Cochran Q or Chi Square test if the results are significant=
heterogeneity
Heterogeneity Degree of overlap in the confidence intervals If there is little over lap?
heterogeneity
Results of a systematic review are
no numbers just gives the number of studies that agree overall picture
Process of A SR: Step 4 A comprehensive, objective, literature search 1. A systematic review is the best evidence but.....
not necessarily the newest evidence
Process of A SR: Step 1 State the ______/______
objective/ question PICO
Note often there are more than ______ _______ for a SR
one comparission 1. mobs vs the ex (moderate) 2. mobs vs no treatment (strong) 3. mobs with exercise vs exercise alone (weak)
If you are only pulling articles from pubmed this creates a publication bias because
only articles that show a signficant effect are publised
Review Articles -provide lots of reference to get their _______
opinion
Process of A SR: Step 5 What term on pico can be very very specific in a SR?
outcome
What is selective reporting bias?
outcomes that are measured but not reported statistically significant outcomes are more likely to be chosen by the author for reporting
What is foundational evidence?
preponderance of evidence from animals, cadaver, or bench studies
Dimensionless measures nominal or ordinal outcome measures WHAT kind of study?
prognosis study
Process of A SR: Step 4 A comprehensive, objective, literature search 1. must avoid
publication bias
The tendency for journal editors to publicize certain study findings but not others
publication bias
How do you find SR/MA
pubmed using filters
