systematic review or meta-analysis

Last reviewed 01/2018

• meta-analysis - this is purely a statistical technique for averaging an effect of treatment across studies
  • a meta-analysis integrates the quantitative findings from separate but similar studies and provides a numerical estimate of the overall effect of interest
• systematic review - this is a process where the investigators will identify the studies that have been undertaken relevant to a particular hypothesis. There may be none or it may be that trials are so different from each other that it makes not sense to try and find the average effect, in which case the reviewers will not undertake a meta-analysis. If there are suitable results from similar studies then these can be combined using a meta-analysis and are generally displayed in a Forest plot
  • Petrie et al describe a systematic review as "... an efficient approach to integrating existing information, invariably a multiplicity of published articles, with a view to establishing whether the scientific findings are consistent. If so, it may be possible to draw conclusions and make recommendations about treatment regimens or observed effects which have greater credence than those obtained from individual studies"
    • the undertaking of a systematic review relies on a specified checklist which determines which articles should be included in the review, and how each should be critically appraised to provide relevant information relating to the focus of the review

Reference:

1. Update (June 16th 2005): 85.
2. Petrie A et al. Further statistics in dentistry Part 8: Systematic reviews and meta-analyses.BDJ 2003; 194(2):73-78.