Steps in A Meta-analysis
1. Formulation of the problem
2. Search of literature
3. Selection of studies ('incorporation criteria')
- Based on quality criteria, e.g. the requirement of randomization and blinding in a clinical trial
- Selection of specific studies on a well-specified subject, e.g. the treatment of breast cancer.
- Decide whether unpublished studies are included to avoid publication bias (file drawer problem)
4. Decide which dependent variables or summary measures are allowed. For instance:
- Differences (discrete data)
- Means (continuous data)
- Hedges' g is a popular summary measure for continuous data that is standardized in order to eliminate scale differences, but it incorporates an index of variation between groups:
-
- in which is the treatment mean, is the control mean, the pooled variance.
5. Model selection (see next paragraph)
For reporting guidelines, see the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement
Read more about this topic: Meta-analysis
Famous quotes containing the word steps:
“Every child has an inner timetable for growth—a pattern unique to him. . . . Growth is not steady, forward, upward progression. It is instead a switchback trail; three steps forward, two back, one around the bushes, and a few simply standing, before another forward leap.”
—Dorothy Corkville Briggs (20th century)