- Introduction to Evidence-Based Nursing
- Structure of Literature
- Research Design
- Searching the Literature
- Evaluating the Quality of Research
- Tutorial Evaluation
Submitted by nursingadmin on Tue, 2006-09-26 16:07
A systematic review is:
A summary of the medical literature that uses explicit methods to perform a comprehensive literature search and critical appraisal of individual studies, and that uses appropriate statistical techniques to combine these valid studies. 
Systematic reviews provide the strongest type of evidence, as the authors attempt to find all research on a topic, published and unpublished. The authors then combine the research into a single analysis. Keep in mind that systematic reviews are different than review articles. While systematic reviews are conducted to answer a specific clinical foreground question, review articles provide a broad overview on a topic to answer background questions. Another difference is that the literature search for review articles does not attempt to find all existing knowledge on a topic.
A meta-analysis is a particular type of systematic review that attempts to combine and summarize quantitative data from multiple studies using sophisticated statistical methodology. Such a strategy strengthens evidence as it makes the small sample size of individual studies much larger, giving the results more statistical power and, therefore, more credibility than the individual studies. Meta-analyses are not comprehensive, as only compatible data may be combined into a larger data set.
Authors should clearly specify the criteria for inclusion or exclusion of individual studies somewhere in a systematic review or meta-analysis.