Nursing Resources: Step 3: Appraise the Evidence

Appraise the Evidence

After you have gathered your evidence, you need to evaluate the quality of  the studies. There are many tools available to help you answer the following questions: 

1. How serious is the risk of bias?
2. Does the study/evidence address my question?
3. Is the source reliable?
4. Is the methodology sound?
5. Are the results valid?
6. Does the evidence apply to my patient or population?

Critical appraisal tools are available from Critical Appraisal Skills Programme (CASP), including freely available worksheets and checklists. 

Synthesizing the Evidence

Synthesis involves combining ideas or results from two or more sources in a meaningful way. In EBP the synthesis is focused on the clinical question. You may combine the details from the article appraisals into themes to organize the ideas. The writing must remain objective and accurately report the information from the original sources.

• Strength of evidence is based on the quantity, quality and consistency (of results) of a body of literature.
  • Quantity: The number of studies available
  • Quality: The level and strength of evidence available
  • Consistency of results: The consistency of the research findings
• Applicability of evidence: Determined by ability for evidence to answer questions

Discuss implications for practice, education, or research. The discussion may include suggestions or recommendations for changes to practice, education or research as well as confirmation of current practice. A table may be used to display the information collected from the articles under discussion.

Synthesis Table