Conducting a Literature Review

Introduction

You've been asked to conduct a literature review, and you might wonder: what exactly does that mean? A literature review (or "lit review") is a structured synthesis of published work within a field of knowledge. It goes beyond a simple list of papers: a strong lit review critically examines, organizes, and interprets both what is known and what remains unknown about a topic.

In academic medicine, lit reviews serve dual purposes. They can be the foundational first step before launching a research project, or a scholarly contribution in their own right. Either way, they require careful planning, systematic searching, and thoughtful synthesis. This guide walks you through the key steps and provides practical tools to help you along the way.

When & Why Should You Conduct a Literature Review?

In research, a lit review is almost always the first step. Before designing a study, you need to know what has already been done: what gaps exist, what methods have been used, and where your work can add new knowledge. This shapes and rationalizes your research question and prevents you from unknowingly duplicating prior work.

As a publication, a lit review can stand on its own as a valuable scholarly contribution. Think of it as a one-stop shop: an article that summarizes and critically analyzes the current evidence on a specific topic, highlights areas of controversy or uncertainty, and points the field toward fruitful avenues for future investigation. High-quality lit reviews are frequently cited, widely read, and can be a meaningful addition to your CV.

• Before starting a research project: Ensures your question is novel, informs study design, and identifies key variables and outcomes used in prior work.
• As part of a manuscript: The Introduction and Discussion sections of any research paper are essentially focused mini-lit reviews.
• As a standalone publication: Synthesizes a topic for the clinical or scientific community, often with broad impact.
• For grant applications: Demonstrates your mastery of the field and justifies why your proposed study is needed.

Types of Literature Reviews

Not all literature reviews are created equal. The type you choose depends on your question, available time, and the depth of evidence synthesis required. Click each type below to learn more.

1. Define the Topic & Scope

This is the most foundational step. Your topic determines what you search for, what you include, and ultimately what you write. Before diving into databases, take time to clearly define both the subject of your review and its scope.

The subject is the broad area of interest (e.g., management of metabolic dysfunction-associated steatotic liver disease, or MASLD). The scope is the lens through which you examine it. One disease can generate dozens of distinct lit reviews covering pathobiology, epidemiology, diagnostic approaches, treatment algorithms, or public health implications, each targeting a different readership and set of questions. Be deliberate about the scope early, or you'll find yourself buried in too many articles with no clear organizing principle.

2. Search the Existing Literature

With your scope defined, it's time to search. A good starting point is to look for existing literature reviews on your topic; they provide a helpful overview and serve as a treasure trove of primary articles for you to explore in depth. From there, expand your search using multiple database sources with a well-constructed search strategy.

Your search strategy should include a range of relevant terms, including synonyms, abbreviations, and alternative phrasings, combined using Boolean operators (AND, OR, NOT). Keep an ongoing and evolving list of search terms as you go, since reading articles often surfaces new vocabulary worth adding to your strategy.

• Search multiple databases: PubMed, Scopus, Web of Science, and Google Scholar each have different strengths (see the interactive section below).
• Keep a running list of your search terms and refine them as you read, since new synonyms and MeSH terms will emerge.
• Prioritize recent primary research articles, but don't ignore landmark older papers that have shaped the field.
• Use a reference manager (e.g., Zotero, EndNote) to track every article you intend to read or cite, starting from the very first search.

3. Organize & Create an Outline

As your article collection grows, resist the urge to start writing immediately. First, digest what you've read and think carefully about how to organize it. The structure you choose should serve your topic, your audience, and the story you're trying to tell.

Two common organizational frameworks in medical lit reviews are:

• Chronological: Structure the review as the field evolved over time. This is particularly effective for topics where the science has undergone major shifts, such as moving from a metabolic framing of NAFLD to the current MASLD nomenclature, or the evolution of HCC treatment from sorafenib to immunotherapy. It naturally leads into "where are we now" and "where do we go from here."
• Thematic: Organize by topic or concept rather than time. For example, a lit review on MASLD might have sections on epidemiology, pathophysiology, diagnostic evaluation, and management. This approach is common for clinical topics where readers may want to jump to a specific subsection.

A well-constructed outline is arguably the most important deliverable before you start writing. It forces you to commit to a structure, reveals gaps in your reading, and gives your mentor something concrete to react to. Your outline should be dynamic, so plan on revising it as you continue reading and drafting.

4. Synthesize, Write, and Edit

With your outline approved, it's time to write. The goal is to synthesize, not simply summarize; this means comparing and contrasting findings, identifying patterns, and offering a critical perspective on what the evidence does and doesn't tell us.

There is no single right way to approach the drafting process. Some people work section by section; others write multiple sections in parallel as they encounter related material. Some read extensively before writing a single word; others start early drafts and refine as they learn. Find what works for you, but don't let perfect be the enemy of done. An imperfect first draft is far more useful than no draft at all.

• Use your outline as a scaffold and work through it section by section.
• Include sub-headings throughout the main body to make the review easier to draft and more navigable for readers.
• The standard structure includes an Introduction, body sections with sub-headings, a Discussion of gaps and future directions, and a Conclusion.
• A strong lit review doesn't just describe findings; it critically appraises them: noting limitations, pointing out conflicting results, and identifying what questions remain open.
• Ask for feedback on drafts early and often. Don't wait until you think it's "ready."

5. Publish or Start Your Research

After multiple rounds of writing and editing, your lit review may be ready for submission. The submission process for a review article follows the same general steps as other manuscripts: selecting a target journal, formatting per their guidelines, writing a cover letter, and responding to peer review.

Alternatively, if your lit review was written to inform a new research project, it has now done its job: you have a thorough understanding of the existing literature, identified a gap, and are ready to design and execute your study. Either way, a well-executed lit review is a valuable scholarly product and a meaningful step in your development as a researcher.

Common Pitfalls to Avoid

• Skipping the scope statement. Starting broad and "figuring it out as you go" leads to an unfocused search, an enormous (and unmanageable) article collection, and a disorganized draft. Define your scope first.
• Using only one database. Each database has different coverage. PubMed alone will miss important articles indexed in Scopus or Web of Science, especially for interdisciplinary topics.
• Not tracking articles from the start. Failing to use a reference manager from day one often means scrambling to reconstruct your reference list at the end. Set up Zotero or EndNote before your first search.
• Summarizing instead of synthesizing. A lit review that reads like an annotated bibliography (article by article) misses the point. Group, compare, and critically interpret findings across studies.
• Getting mentor input too late. Share your outline before drafting. Mentors often have specific angles, key papers, or structural preferences that can fundamentally reshape the project. Early input prevents wasted effort.
• Ignoring limitations and controversies. A review that only reports positive findings is not a critical synthesis. Acknowledge conflicting evidence, methodological limitations, and ongoing debates; this is where the real intellectual contribution lies.
• Not checking journal formatting guidelines early. Word limits, number of references allowed, and required sections vary widely by journal. Discovering these constraints after you've written 6,000 words is painful.

Conclusion

A strong literature review has a clearly defined scope and offers the field a thoughtful, critical analysis of the most up-to-date research. It doesn't just summarize; it synthesizes, identifies gaps, highlights controversies, and points toward future directions. Whether it becomes a publication in its own right or the springboard for your next research project, a well-executed lit review is one of the most valuable scholarly exercises you can undertake as a trainee.

Start with a clear scope. Search systematically. Organize before you write. Synthesize rather than summarize. Get feedback early. And use the interactive tools below to build your search strategy and explore the databases available to you.

Interactive Tools

Use these tools to explore the major literature databases and build a starter search strategy for your review.

Continue Learning

Related modules in the Research Curriculum:

• How to Identify a Research Question
• Organizing Citations with Reference Managers
• How to Write a Research Abstract
• Finding the Right Journal
• How to Write a Cover Letter
• Return to Research Curriculum