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An Introduction to Systematic Review An Introduction to Systematic Review Session1 Roya Kelishadi,MD Feb2014 Child Growth and Development Research Center, Isfahan University of Medical Sciences,Isfahan,Iran

Importance: Many research studies published in medical journals are too poorly done or insufficiently relevant to be clinically useful

Too much information, too little time! There is simply too much information around for people to keep up to date. On top of this, high quality information is often not easy to find.

Levels of evidence

Publication food chain Anecdotal Expert opinion Case reports Case-control studies Cohort studies Randomised controlled trials Reviews and meta-analyses

What is a review article? synthesisconclusions A ‘review’ is the generic term for any attempt to synthesis the results and conclusions of two or more publications on a given topic. Some reviews are usually based on narrative or commentary and are produced by a ‘content expert’

Bias in reviews There are three possible sources of bias in reviews: bias arising from the studies included in the review bias arising from the studies not included in the review bias arising from the way the review is done.

What is a Systematic Review? It comprehensively locates evaluates synthesizes all the available literature on a given topic using a strict scientific design which must itself be reported in the review. The ‘systematic’ part of systematic reviews is all about minimizing bias in the way the review is conducted.

Summary: Types of reviews Systematic reviews: Use explicit and rigorous methods to identify, critically appraise, and synthesize relevant studies Narrative reviews: Summaries of research that lack explicit descriptions of systematic methods Meta-analysis: quantitative review using statistical analyses Meta-ethnography: systematic review of qualitative data

12 “It is surely a great criticism of our profession that we have not organised a critical summary, by specialty or subspecialty, adapted periodically, of all relevant randomised controlled trials.” Archie Cochrane The Cochrane Collaboration

Established in 1993 International, non-profit, independent organisation Promotes evidence of the effects of therapies Production and dissemination of systematic reviews There are > 11,500 people working within The Cochrane Collaboration in over 90 countries. 50% are authors of Cochrane Reviews Cochrane Collaboration

Simply…

Parts of a systematic review

Steps

19 Formulating review questions Searching & selecting studies Study quality assessment Data synthesis Extracting data from studies Development of a review protocol

The literature The literature maze

Before entering the maze… Formulate your question! Pragmatic, well-focused questions Need to know what we are asking, in order to know what studies we include in the review.

Question components : PICO W hat types of P articipants? W hat types of I nterventions? W hat types of C omparison? W hat types of O utcomes?

A broad or a narrow question?

P opulation

Special populations?

I ntervention

C omparison

O utcomes

Turning a question to a title

Exercise:

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