Class 9 Flashcards
(15 cards)
Systematic review
a review that methodically integrates research
evidence about a specific research question using careful sampling and data collection procedures that are spelled out in advance in a protocol
Systematic review (3)
- A primary study (original research investigation)
- Reproducible, verifiable, and transparent
- Cornerstone of evidence evidence-based practice (EBP)
Meta analysis
- A technique for quantitatively (statistically) integrating the results of multiple similar studies addressing the same research question
- The majority of the systematic reviews in the Cochrane Collaboration
Metasynthesis
•A grand narratives produced from the integration or comparison of findings
from multiple qualitative studies, yielding new insights and interpretations
Mixed studies reviews
•Methodically integrates and synthesizes findings from quantitative,
qualitative, and mixed methods studies on a topic
Meta Analyses (quantitative): Advantages
•Meta analyses of RCTS are considered the pinnacle of evidence hierarchies for establishing causation
•Information from each study in the review is used to develop a common metric, the effect size
•Effect sizes are averaged across studies, yielding aggregated information about not only the existence of a relationship between variables, but also an estimate of its magnitude
•Objectivity : other analysts using the same data set would reach the same conclusions
•Power is increased: The probability of detecting a true relationship between the exposure and
outcome variables: the relationship is real even when several small studies yielded non significant findings
•Precision is enhanced: Meta analysts can draw conclusions about how big an effect an intervention
has, with a specified probability that the results are accurate: estimates of effect size across multiple studies yield smaller confidence intervals than individual studies
The research question being addressed across studies must be
the same or strongly similar. Exposure and outcome variables and study populations must be sufficiently
similar to merit integrations
PRISMA
guideline for systematic review
Retrieve as many relevant studies as possible!
- Hand search journals known to publish relevant content
- Identify and contact key researchers in the field to see if they have done studies that have not (yet) been published, and about other members of the “invisible college”
- Author search key researchers in the field in bibliographic databases and the Internet
- Review abstracts from conference proceedings, and network with researchers at conferences
- Search for unpublished reports, such as dissertations and theses, government reports, and registries of studies in progress
- Contact foundations, government agencies, or corporate sponsors of the type of research under study to get leads on work in progress or recently completed
Want low or high heterogenity
low
Publication bias:
•Authors tend to refrain from submitting manuscripts with negative findings
•Reviewers and editors tend to reject such papers when they are submitted, and
•Users of evidence tend to ignore the findings when they are published.
Results in the overestimation of effects
Funnel Plot
•A graph designed to check for the existence of
publication bias, commonly used in systematic
reviews and meta analyses.
•In the absence of publication bias, it assumes that
studies with high precision will be plotted near the
average, and studies with low precision will be
spread evenly on both sides of the average,
creating a roughly funnel shaped distribution.
•Deviation from this shape can indicate publication
bias.
Evaluate study quality
- In systematic reviews, the evidence from primary studies should be evaluated to determine how much confidence to place in the findings
- Strong studies should be given more weight than weaker ones in coming to conclusions about a body of evidence
- Coding for quality elements in primary studies should be done by at least two qualified individuals. If there are disagreements between the coders, there should be a discussion until a consensus has been reached or, if necessary, a third person should be asked to help resolve the difference.
- Interrater reliability can be calculated to demonstrate to readers that rater agreement on study quality elements was adequate.
Avoiding illegitimate open
access journals
•Journal web site is difficult to locate or identify
•Publisher “About” information is absent on the journal’s web site
•Publisher direct marketing (i.e., spamming) or other advertising is obtrusive
•Instructions to authors information is not available
•Information on peer review and copyright is absent or unclear on the journal web site
•Journal scope statement is absent or extremely vague
•No information is provided about the publisher, or the information provided does not
clearly indicate a relationship to a mission to disseminate research content
•Repeat lead authors in same issue
•Publisher has a negative reputation
Predatory scholarly publications
- Predatory publishers are publishers who focus on generating profits without regard to the quality of what they publish.
- They make extravagant promises and then, once contracts are signed and money has changed hands, they fail to deliver.
- They are sometimes also called vanity presses, or described as fraudulent, deceptive, or fake.
