A medical literature review flows from question to methods, results, synthesis, and implications, reported with transparent steps and criteria.
A clinical evidence overview lives or dies on structure. Readers want to see what question you asked, how you searched, which reports you kept, how you judged quality, and what the combined evidence means for care or research. The format below mirrors what journals, peer reviewers, and indexing services look for, while staying readable for busy clinicians.
Structure Of A Literature Review In Medicine: Section-By-Section
Most clinical evidence summaries track the same arc. Use the outline below as your base, then adapt to your discipline and journal style. Keep paragraphs tight, use topic sentences, and place methods where readers expect them, not scattered across sections.
| Section | Purpose | What To Write |
|---|---|---|
| Introduction | Set clinical context and gap | Define the problem, link to patient or system impact, end with a clear review question |
| Methods | Show how evidence was gathered | Sources, dates, search strings, eligibility criteria, screening, data extraction, bias appraisal, synthesis plan |
| Results | Report what you found | Study flow, study characteristics, risk-of-bias summary, key outcomes, effect estimates when applicable |
| Synthesis | Combine findings | Narrative themes or pooled effects, heterogeneity handling, sensitivity checks |
| Discussion | Interpretation and limits | What the evidence means, where it falls short, clinical and research implications |
| References/Appendices | Traceability | Full citations, search strategies, data forms, excluded-study list with reasons |
Define The Question And Scope
Open by naming the clinical decision or policy choice that depends on better evidence. Avoid generic claims. State the gap that prompts the review and end the section with a single-sentence question. If your topic involves treatment choice, PICO framing (Population, Intervention, Comparator, Outcomes) keeps scope tight. For diagnostics, use a version aligned to index test and reference standard. For prognosis, define setting, time horizon, and outcomes that matter to patients.
Choose The Review Type
Pick an approach that matches your aim. A scoping review maps concepts and methods across a field. A systematic review targets a focused question with pre-set criteria and a reproducible process. A rapid review trades breadth for speed using streamlined steps. State the type early and keep your choices consistent with that label across the paper.
Methods That Editors Expect
Methods are the backbone. Readers must be able to re-run your process and reach similar included sets. Write in past tense, keep subsections in a fixed order, and place enough detail in the main text to be self-contained, with long strings and forms in appendices.
Sources And Search Strategy
List every database and register you used, with search dates and any language or year limits. Provide at least one full search string for a primary source, then note how you adapted it elsewhere. If you added citation chasing, trial registries, or preprint servers, say so and describe the steps. Librarian review boosts quality; credit that support in acknowledgments when allowed.
Eligibility Criteria
Spell out inclusion and exclusion rules in plain terms. Typical elements are study design, population, intervention or exposure, comparator, outcomes, setting, and minimum follow-up. Link each rule to your question, not to convenience. If you exclude non-English texts or small samples, justify the choice and discuss the risk of selection bias later.
Study Selection Workflow
Describe how you screened records: number of reviewers, independence of screening, conflict resolution, and the software used. Distinguish record-level screening (titles/abstracts) from full-text review. Keep a reasoned audit trail for exclusions at full text; you will summarize counts in the flow diagram and list common reasons in text or appendix.
Data Extraction Plan
List the fields you captured: study identifiers, setting, sample size, eligibility features, interventions, outcome definitions, time points, and numeric results. Note any hierarchy for multiple measures of the same endpoint. Mention calibration runs, duplicate extraction for a subset, and how disagreements were settled.
Quality And Bias Appraisal
Name the tool matched to design: randomized trials often use a domain-based tool; cohort or case-control studies use an observational checklist; diagnostic accuracy studies use a diagnostic-specific tool. Explain scoring or domain judgments and how they inform synthesis, such as excluding high-risk reports from pooling or using sensitivity checks.
Synthesis And Statistics Plan
State up front whether you plan a narrative summary, a meta-analysis, or both. For pooling, name the effect measure (risk ratio, odds ratio, mean difference, standardized mean difference), the model, and how you assess heterogeneity. Describe subgroup plans set before analysis and how you will handle small-study effects.
Results And Synthesis
Results should mirror methods. Report what the search found, what you kept, and why. Keep this section descriptive and reserved for findings; save interpretation for the next section.
Study Selection Summary
Present the flow from records identified to reports included, with counts for each stage and common exclusion reasons. Many journals expect a diagram that follows a standard template; the PRISMA 2020 checklist lays out the items and the matching flow figure used across health research. Cite the number of unique records after de-duplication, then the number screened, retrieved as full text, excluded at full text, and included for synthesis.
Characteristics Of Included Studies
Give readers a way to compare studies at a glance: setting, time period, sample size, eligibility, exposures or interventions, comparators, and measured outcomes. Place the granular details in a table and keep the prose focused on patterns that explain variation across results, such as dose, timing, or risk profiles.
Risk Of Bias Across Studies
Summarize common concerns by domain. Typical issues include sequence generation, allocation concealment, blinding, missing data, selective reporting, and measurement differences. Keep this part short in the body and place full tool judgments in an appendix or figure with domains on one axis and studies on the other.
Qualitative Synthesis
When pooling is not sensible, group findings by theme: care setting, population segment, or intervention class. Point out consistent effects, null results, and conflicts, tied to design or quality differences. Quote a few cardinal numbers in text for anchor points and leave the rest to tables and figures.
When Meta-Analysis Fits
If studies line up on design and outcome, present pooled estimates with uncertainty and heterogeneity stats. Explain choices such as model type and any transformations. If you run subgroup or sensitivity checks, state why a split was chosen and whether it changes the picture. Keep plots clean and readable, with the same outcome direction across panels.
Discussion: Meaning, Limits, And Next Steps
Now you can interpret. Tie back to the opening question and state what a clinician, policymaker, or researcher can do with these results. Keep claims inside the guardrails of your methods and the included evidence. Use plain language, short sentences, and avoid overreach.
Strengths And Limits
Be frank about constraints: search coverage, language limits, surrogate endpoints, short follow-up, or reliance on small samples. Note any signals of publication bias, selective outcome reporting, or confounding. Balance this by stating where the process excelled, such as protocol registration, duplicate screening, or public code.
Practice And Research Gaps
Close with clear actions. Give a one-line takeaway for practice if the evidence is consistent, or a one-line caution if results conflict. Flag the studies that would sharpen the picture: longer follow-up, head-to-head comparisons, patient-centered outcomes, or pragmatic designs.
For section names and reporting order used by many journals, see the Cochrane guidance on review reporting, which maps headings and expected content across methods and results (Cochrane reporting chapter).
Common Mistakes And Easy Fixes
Editors see the same preventable issues over and over. Use the table below during drafting and before submission.
| Pitfall | Why It Hurts | Quick Fix |
|---|---|---|
| Vague question | Scope drifts and results feel scattered | Lock a PICO-style question and stick to it |
| Thin methods | Readers cannot reproduce the process | Add databases, dates, strings, and workflows |
| No flow diagram | Selection path is unclear | Include a standard study flow figure with counts |
| Mixing results with opinions | Signal gets lost | Keep interpretation in Discussion, not in Results |
| Ignoring bias | Overstates confidence | Use a design-matched tool and report domains |
| Over-pooled meta-analysis | Combines apples and oranges | Pool only when designs and outcomes align |
Formatting, Style, And Submission Tips
House style varies, but the backbone stays the same. Keep the reader’s path friction-free: headings that predict content, figures that read at a glance, and references that resolve cleanly.
Title And Abstract
Use a clear, specific title that names the population and topic. Write a structured abstract with the same order as the main text: background, objective, data sources, eligibility, methods, results, and implications. If a registry or protocol exists, cite the identifier in the abstract and again in the main text.
Figures, Tables, And Appendices
Use figures for study flow and pooled effects, tables for characteristics and outcomes. Keep each table to a focused aim. Place long search strings, data forms, and excluded-study lists in appendices to keep the body readable while preserving traceability.
Language And Tone
Short sentences help busy readers. Use field terms where needed, but define them on first use. Avoid inflated claims. Numbers beat adjectives. When you cite outcomes, give absolute values along with relative measures when space allows.
Transparency Checklist
Run a formal check before submission. The PRISMA 2020 checklist maps line by line what a complete report contains. If your review is diagnostic, prognostic, or scoping, find the matched template via the EQUATOR guideline finder and align section order and required items.
Section-By-Section Writing Prompts
Introduction
Start with one tight paragraph that names the clinical problem and why current guidance falls short. Follow with a short paragraph on the signal you will look for (benefit, harm, accuracy, prognosis). End with a one-line objective that pins down population, exposure or intervention, comparator, and outcomes.
Methods
Write subsections in this order: Sources; Search Strategy; Eligibility; Screening; Data Items; Bias Appraisal; Synthesis Plan; Registration and Protocol; Deviations From Protocol. Keep each to a few sentences. Add exact search strings and forms in an appendix and reference them in the text.
Results
Open with record counts and the study flow. Move to a characteristics table and a paragraph on overall design patterns. Then present main outcomes in a logical sequence. If you pooled effects, present the primary endpoint first, then prespecified subgroups, then sensitivity checks. Keep outcome direction the same throughout to avoid confusion.
Synthesis
For narrative synthesis, group by theme and link patterns to design or quality. For pooled analyses, explain model choice in one line, report the pooled effect with a confidence interval, and add a plain statement about clinical meaning. If heterogeneity is large, say what trait best explains it and how that shapes confidence.
Discussion
Offer a measured take. State where the evidence is strong, where it is thin, and what a clinician can do on Monday morning. List two or three precise research tasks that would move the field: longer follow-up in a high-risk subgroup, a head-to-head comparison, or a patient-reported endpoint at a standard time point.
Ethics, Registration, And Data Sharing
Most evidence summaries use published, de-identified material and do not require ethics board review, but journal policies vary. Registration or a time-stamped protocol improves credibility by showing what you planned before seeing results. Public data and code improve reuse; place them in a stable repository and link from the paper.
Checklist You Can Copy Into Your Notes
- Scope set with a single-sentence question and matched review type
- Named databases and registers, dates, full string for at least one source
- Transparent screening with counts and reasons at full text
- Clear eligibility rules tied to the question
- Defined data items with a plan for ties and multiple measures
- Design-matched bias tool with domain summary
- Pre-stated synthesis plan, model, and effect measures
- Flow figure with counts at each stage
- Characteristics table and outcome table aligned to the question
- Measured, plain-language interpretation with limits and next steps
Submission And Peer Review Prep
Before you send, check author instructions for word limits, figure caps, and reference style. Make sure tables fit mobile screens and that figure text is readable at common viewport widths. Confirm that links resolve to stable pages and that any supplement files open cleanly without sign-in. A short cover letter that names the question, the method used, and the main takeaway helps editors place the work quickly.
Final Pass: Reader Experience
Scan your page like a busy clinician would: does the opening confirm the topic fast, can a reader find methods without hunting, and do figures tell the story without dense text? Trim repetition, promote numbers over adjectives, and keep headings honest about what follows. The result is a clear, credible review that supports care and future studies.