An Introduction to Meta-analysis
Sportscience 8, 20-24, 2004
Update March 2014. Added a forest and moderator plot; mentioned mediator plot.
Update Oct 2013. Substantial make-over to take into account the unified approach to ratios of risks or proportions, odds, hazards and counts in the article on linear models and effect magnitudes. A novel approach of including separate effects for each group from controlled trials or other studies with control, reference or other comparison groups is also described.
The basis for this article is an
updated version of a slideshow accompanying a talk on meta-analysis I
presented this year locally and at the
My experience with meta-analysis is limited–one analysis published and three others completed recently–but most of my assertions appear to be consistent with those in the ultimate source of meta-analytic wisdom, the handbook of the Cochrane Collaboration (cochrane.org) I depart from the handbook with my emphasis or novel material on individual responses, standardized differences in means, log transformation, measures of physical performance, and correlations. You will need to refer to the Cochrane handbook for information on topics I don't cover, including survival analysis, intention-to-treat analysis, and meta-analysis of single-subject studies (cases or individual patient data).