Why Review Articles?

Evidence is available in many forms, for example:

• Articles about an individual research study,
• A synthesis of numerous research studies (systematic or integrated reviews or meta-analyses),
• Clinical guidelines, and
• Professional position statements.

Articles that synthesize numerous research studies were chosen as the primary form of evidence to display in this Resource Area because syntheses, such as integrated or systematic reviews and meta-analyses, provide a summary of evidence across multiple research studies in a manner that can be most readily evaluated and incorporated into practice.

An integrated or systematic review published in the literature provides a narrative or qualitative synthesis of quantitative research findings about a clinical problem (Ropka & Spencer-Cisek, 2001).

A meta-analysis can be thought of as a quantitative analysis and synthesis of quantitative research findings -a "study of studies". In a meta-analysis, statistical analyses are done using the data from already published studies (LoBiondo-Wood & Haber, 2002) to calculate measures such as effect sizes. A meta-analysis may confirm existing findings from individual studies or clarify conflicting findings.

Finding a relevant integrated review or meta-analysis in the current literature can "jump-start" an evidence-based project. The published synthesis may be all that is needed if it is current and comprehensive enough. If the review is not current or comprehensive it can be used as a blueprint and a planning group can add the most current evidence (DePalma & McGuire, 2005).

Cochrane Library’s systematic reviews are the gold standard of research syntheses. Abstracts can be searched for at http://www.cochranelibrary.net/cochrane/abstract.htm. Full review documents are available for a charge or at no charge if your organization is a subscriber.