How to Conduct a Systematic Review

Narrative literature reviews have an important role in continuing education because they provide readers with up-to-date knowledge about a specific topic or theme and add dimensions of insight that are not available in any one single empirical study. However, this type of review does not describe the methodological approach that would permit reproduction of data nor answer to specific quantitative research questions.

On the other hand, systematic literature review is a well-planned review to answer specific research questions using a systematic and explicit methodology to identify, select, and critically evaluate results of the studies included in the literature review.  Systematic literature review articles are considered original work because they are conducted using rigorous methodological approaches. Methodological approaches to conduct a systematic literature review can be found in Cochrane Handbook of Systematic Reviews of Interventions published by the Cochrane Collaboration.  The Cochrane Collaboration recommends seven steps to conducting a systematic review:

1. Pose a Research Question – A systematic literature review must start with a well formulated research question that contains well defined types of patients/illness and interventions that help in the decision-making process determining which articles to include in the literature review.
2. Locate Studies – Use several sources to locate and retrieve scientific studies. These sources should include all relevant scientific databases as well as conference proceedings and relevant grey literature as described under “Literature search / Lesson 1: Where to search”. A detailed description of the approach should be described for each one of these types of sources used.
3. Critically Evaluate the Studies – Use specific criteria to determine the validity of the selected studies. This approach facilitates the decision-making process determining which articles would be included in the literature review. Studies that are not included in the literature review must be cited and have a rationale for exclusion.
4. Collect Data – Describe each study’s methodological approach (variables, sample, measures, and data analysis) and findings, which allow comparison between and/or among the selected studies.
5. Analyse Data and Report – Studies should be grouped together according to their methodological similarities. This approach must be addressed in the project. Numerical and graphical presentation of the results should also be addressed in the project to facilitate reader understanding of the findings. Statistical analysis and synthesis of the results consists of meta-analysis, a statistical method to integrate the results of systematic reviews. 
6. Interprete the Findings – This is determined by the strength of evidence, utilization of the findings, costs and current practice, which dictates the balance between benefits and risks.
7. Refine and Update the Review – When published, a systematic review will be scrutinized by the scientific community who will then make recommendations that must be addressed in subsequent reviews, updating the review topic when new studies about the topic are published.