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Evidence Based Nursing

This guide provides information on evidence based practice in nursing

What is a Systematic Review?

A video from the Cochrane Consumers and Communication group.

Cochrane Database

Cochrane Database of Systematic Reviews     

Contains full text articles, as well as protocols focusing on the effects of healthcare. Data is evidence-based and is often combined statistically (with meta-analysis) to increase the power of the findings of numerous studies, each too small to produce reliable results individually.

Systematic Review visualized

Steps in Developing a Systematic Review 

1. Define the question - a clearly defined question will ensure that your research produces relevant results. 

2. Write the protocol, which includes the inclusion/exclusion and eligibility criteria. The protocol defines the process for selecting studies and reduces the risk of bias. 

3. Register your protocol. 

4. Develop the search strategy. 

5. Identify any recent or ongoing system reviews. 

6. Search relevant sources to identify the evidence. 

7. Appraise and select suitable studies 

8. Synthesize the data. 

9. Document and report the search strategy. 

What is a Systematic Review?

A systematic review attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question. It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions can be made. The key characteristics of a systematic review are: 

  • a clearly stated set of objectives with predefined eligibility criteria for studies.
  • an explicit, reproducible methodology.
  • a systematic search that attempts to identify all studies that would mee the eligibility criteria.
  • an assessment of the validity of the findings of the included studies, from example through the assessment of risk of bias.
  • a systematic presentation, and synthesis, of the characteristics and findings of the included studies. 


Higgins, J. & Green, S. (Ed.). (2011). Cochrane Handbook for Systematic Reviews of Interventions. (5th ed.). Retrieved from


Why is it important to have a plan? 

A major cause of bias in a systematic review is answering a different question to that being originally asked. This is why it is important to develop a review plan or protocol. 

The benefits of having a protocol before the beginning of a review:

  • relate the validity and merit of a research process that reduces risk of bias. 
  • promotes a systematic rather than ad hoc approach to the review process.
  • facilitates communication with others and promotes consistency between review team members. 
  • supports the reliability and usefulness of reviews to health professionals. 

The protocol should include: 

  • review questions/objective 
  • inclusion/exclusion criteria (Scope including types of studies, participants, interventions) 
  • search strategy 
  • methodology 
  • declaration of interests