PT  - JOURNAL ARTICLE
AU  - Matthias Egger
AU  - George Davey Smith
AU  - Jonathan A C Sterne
TI  - Uses and abuses of meta-analysis
AID  - 10.7861/clinmedicine.1-6-478
DP  - 2001 Nov 01
TA  - Clinical Medicine
PG  - 478--484
VI  - 1
IP  - 6
4099  - http://www.rcpjournals.org/content/1/6/478.short
4100  - http://www.rcpjournals.org/content/1/6/478.full
SO  - Clin Med2001 Nov 01; 1
AB  - Meta-analysis, the statistical combination of results from several studies to produce a single estimate of the effect of a treatment, continues to attract controversy. We illustrate the potentials and pitfalls of meta-analysis of controlled clinical trials. Cumulative meta-analysis demonstrates that this technique could prevent delays in the introduction of effective treatments. Meta-analyses are, however, liable to numerous biases both at the level of the individual trial (‘garbage in, garbage out’) and the dissemination of trial results (publication bias). We argue that meta-analysis should be performed only within the framework of systematic reviews - that is, reviews prepared using a systematic approach to minimise bias and address the combinability of studies.