Narrative reviews provide a rich, illustrative overview of existing research on a topic. Their aim is to summarize what is known about a topic, including key concepts, debates, and gaps in knowledge. Narrative reviews use a flexible methodology to select, analyze, and synthesize research, rather than a structured systematic framework, allowing for conceptual synthesis rather than exhaustive coverage.

Narrative reviews are appropriate when: 

• Time is limited (e.g., a couple of months rather than a year). 
• A qualitative approach to synthesizing literature is appropriate.
• Background knowledge is needed for bench research, case reports, or grant applications.

Which type of narrative review is right for you?

Narrative review is an umbrella term that encompasses a wide range of approaches to interpretive synthesis of the available literature on a topic. These approaches vary in purpose and level of methodological structure. Here are a few of them:

• A general literature review is the most common approach to a narrative review. It identifies themes in the literature and presents areas for future research. 
• A critical review is a more subjective, qualitative approach to discussing literature. It is often guided by a theoretical framework that questions the dominant narrative’s assumptions.
• A state-of-the-art literature review is a style of synthesis that provides an overview of developments in the field and identifies future pathways for research. In addition to discussing a topic’s chronological timeline, it also focuses on recent advances and emerging trends.
• A consensus review is a type of narrative review that occurs when a group with expertise on the research topic reviews and synthesizes the literature to reach a joint conclusion. 

How do you conduct a narrative review?

Preliminary topic investigation

Examine the existing literature before diving into your principal search. This step is referred to as preliminary topic investigation, and it is necessary to conduct it before beginning a more thorough literature review. If skipped, your research project could end up being duplicative of what has already been done.

The findings from the preliminary search may indicate a need to revise your research focus, particularly if you discover gaps, overlaps, or limitations in the existing literature. 

Research question

Once you’ve completed your preliminary search, you’ll need to develop a well-structured research question. From there, break down your research question into two or three main concepts before beginning your more targeted search in the various databases that cover your topic. 

Search strategy

For a narrative review, the search strategy strives to capture sufficient relevant literature to effectively synthesize the literature on your research topic. While narrative reviews do not require fully reproducible or exhaustive searches, it is still important to use transparent and well-documented methods. The desired number of results is subjective depending on the research topic, and for this type of review you might employ strategies to filter and manage a large number of results.

Evaluation

When choosing which articles to include in your narrative review, evaluate their relevance and credibility. For example: 

• How does the study support its claims with evidence?
• What is the author’s purpose?
• Is the information relevant to my research topic?
• When was this article published?
• What are the authors’ qualifications?
• What organization produced the work, and what is its mission?

Synthesis

When synthesizing the literature, focus on answering the research question introduced at the beginning of the review.

The discussion in the narrative review should be more than just a summary of the sources. Consider including answers to the following: 

• Which themes appear repeatedly in the literature?
• Which subtopics highlight gaps in the research?
• How can this review identify future research directions?

One way to keep track of the search results is through a literature matrix. A literature matrix is a spreadsheet that tracks each paper’s characteristics, such as its limitations or theoretical framework. The matrix supports comparison across studies and helps identify patterns in the literature. Here is a sample literature matrix template (Excel spreadsheet) that you can download and adapt for your research.  

What are the limitations of a narrative review?

Because narrative reviews are not systematic, they have several limitations: 

• Potential bias: Bias can arise in how evidence is searched, selected, interpreted, or presented, which may affect the balance and accuracy of conclusions.
• Limited reproducibility: Searches are not exhaustive and may not be reproducible, which reduces transparency and can limit objectivity.

Best practices

As you search the databases and gather literature, it is essential to document your steps so you can justify your choices. This documentation would include the database(s) searched, what interface the database is hosted on, the date of the search, and the number of results.

Citation managers can help organize your literature collection and often allow you to download a filtered subset to a spreadsheet to ease your documentation. Documentation supports transparency, reproducibility, and efficiency during synthesis and writing.