A systematic review is a literature review in response to a focused question. Authors of systematic reviews follow the scientific method to identify, select, assess and synthesize the research available. The result is a transparent synthesis and critical appraisal of the best quality research. For example, a Cochrane review may ask: what interventions are effective in reducing mother-to-child infection of HIV?

Researchers may find systematic reviews useful when planning research to:

• avoid duplication - the extensive literature searches in a systematic review identify research already completed
• avoid unnecessary repetition - if meta-analyses clearly show consistent results from existing trials there is likely no need to replicate research in this area
• identify new areas of research - if a review finds no research available, a gap in research is identified that needs to be addressed

The Cochrane Collaboration is a global not-for-profit organization that produces the 'gold standard' in systematic reviews. Cochrane reviews explore the research evidence about the effectiveness and appropriateness of interventions for medical conditions and the delivery of health care.

Cochrane reviews are published in a searchable database, The Cochrane Library. Reviews are updated every 3-4 years as new research emerges.

Resources

• What is a Cochrane review?
• The Cochrane Library
• Podcasts - listen to summaries of reviews
• Online tutorials - searching The Cochrane Library
• Cochrane Handbook for Systematic Reviews of Interventions
• Cochrane Methods Groups
• The Cochrane Journal Club