A medical literature review is written by framing a question, planning database searches, screening studies, appraising quality, and synthesizing findings.
Writers in health and biomedicine use a repeatable plan to move from a clinical or policy question to a clear summary that others can trust. Below is a clear roadmap that shows what to do, the order to do it, and what to deliver at the end.
Writing A Medical Literature Review: Step-By-Step Plan
This plan suits coursework and journal submissions. It scales up or down and keeps methods transparent so readers can see how you reached your findings.
Define The Question
Start with a focused question. Many teams use PICO (Population, Intervention, Comparison, Outcome) for trials, PEO (Population, Exposure, Outcome) for exposure questions, or PICo for qualitative topics. Name the setting, time frame, and outcomes that matter. List primary and secondary outcomes so screening stays consistent.
Draft A Protocol
Write a short protocol that sets your aim, eligibility criteria, databases, search strings, data items, and appraisal tools. Add who will screen, who will extract data, and how conflicts get resolved. For large projects, register the protocol in a public registry such as PROSPERO to create a time-stamped record.
Plan The Search
Pick databases that fit the topic: MEDLINE via PubMed, Embase, CINAHL, PsycINFO, Web of Science, and trial registries. Use both text words and controlled vocabulary such as MeSH. Combine terms with Boolean operators (AND, OR, NOT). Add filters for study design only if they are validated and fit your aim. Record every string and date so the search is reproducible.
Core Elements And Work Order
The table below keeps the moving parts straight in the first pass. Adjust the scope to match deadlines, but keep the logic intact.
| Stage | Deliverable | Good Practice |
|---|---|---|
| Question | PICO/PEO statement | Define outcomes and time window |
| Protocol | Methods plan | State inclusion/exclusion rules |
| Search | Database strings | Use MeSH and text words |
| Screen | PRISMA counts | Dual screening when possible |
| Extract | Data table | Pilot the form on 3–5 studies |
| Appraise | Bias ratings | Pick tools matched to design |
| Synthesize | Narrative or meta-analysis | Explain heterogeneity |
| Report | Structured manuscript | Follow a reporting checklist |
Screen Studies Without Losing Track
Export all records to a reference manager and remove duplicates. Screen titles and abstracts against eligibility rules, then check full texts. Log reasons for exclusion. Many groups chart the numbers in a flow diagram so readers can see what was found and what was dropped.
Choose Appraisal Tools That Fit Design
Trials often use RoB 2 for bias assessment, cohort and case-control studies use tools such as ROBINS-I or Newcastle–Ottawa, and qualitative work uses checklists tailored to its methods. Use two reviewers for high-stakes decisions. Calibrate on a few papers first to align judgments.
Extract The Right Data
Create a form that captures study setting, design, sample size, participant features, exposure or intervention details, outcomes, follow-up, effect estimates, and any funding or conflict notes. Note which adjusted model to prefer and where to find it.
Synthesis: From Piles Of Papers To Clear Findings
When studies share design and outcomes, pool them in a meta-analysis. If data are sparse or designs differ, use a structured narrative. Either way, group findings by outcome, time point, and population. Comment on direction and size of effects, not just p-values.
Handle Heterogeneity
Plan subgroup or sensitivity checks only when they answer a prespecified question. Look at clinical diversity (who, what, where), methodological diversity (design, bias), and statistical diversity. Avoid data-driven fishing. Report what you planned and what changed with reasons.
Write With A Proven Template
Use a structured abstract, an introduction that grounds the need, a methods section that lets another team repeat your steps, results in a logical order, and a section that explains what the findings mean for practice, policy, or research gaps. State limits of the evidence and of your process.
Use Reporting Standards Readers Expect
Two resources anchor clear reporting in health research: the PRISMA 2020 checklist and the Cochrane risk-of-bias guidance. Link your methods and tables to these so editors and reviewers can map your work to accepted standards.
Map Methods To PRISMA Items
PRISMA lays out what to report in the title, abstract, methods, results, and more. It also provides a flow diagram for study selection. Many journals require it for intervention reviews. You can cite items by number inside your draft to make final checks easy.
Apply RoB 2 For Trials
RoB 2 structures bias judgments into domains such as the randomization process, deviations from intended interventions, missing outcome data, outcome measurement, and selection of the reported result. Record the signaling answers, rules, and overall judgment. Present a summary table in results.
Search Strategy That Stands Up To Scrutiny
Start with a small set of seed papers and extract controlled terms and text words from them. Build strings for each concept, then combine concepts with AND. Within a concept, link synonyms with OR. Use truncation and field tags when the database allows it. Test recall by checking that known key papers appear.
Grey Literature And Trial Registries
Add conference abstracts, dissertations, and clinical trial registries if the topic is prone to publication bias. Document every source and date. If time is short, state which sources were not searched and why.
Document Everything
Keep a methods log: dates searched, platforms, exact strings, number screened at each stage, forms used, and any changes to protocol. This log shortens peer review and makes updates easy later.
Results Section: What Readers Want First
Open with the study selection numbers and the flow figure. Then give a study table that lists design, setting, and sample. Next, present outcomes in a fixed order that mirrors your protocol. Keep figures readable on a phone screen.
Write Plain, Actionable Conclusions
State what the evidence supports, where evidence is uncertain, and what decision a practitioner or policymaker could make today. Distinguish between absence of evidence and evidence of no effect.
Quality Control Before You Hit Submit
Run a short audit using the checklist below. This cuts revisions and speeds acceptance.
| Issue | Symptom | Fix |
|---|---|---|
| Vague question | Outcomes vary across papers | Refine PICO/PEO |
| Weak search | Key studies missing | Add MeSH and synonyms |
| Poor tracking | Counts don’t add up | Use a flow diagram |
| Bias not assessed | Claims feel shaky | Apply design-matched tools |
| Thin synthesis | Only quotes or p-values | Group by outcome and time |
| Overreach | Claims outstrip data | Mark certainty and limits |
Formatting Details That Help Editors Say Yes
Use short paragraphs and informative subheads. Keep tables under three columns when viewed on mobile. Number figures and tables in the order they appear. Provide captions that describe what the reader should see without restating the entire result.
Figures And Appendices That Pull Weight
Include the flow figure, a risk-of-bias summary, any forest plots, and the full search strings in an appendix. If you raise or lower certainty due to bias, imprecision, inconsistency, or indirectness, state it plainly.
Ethics, Transparency, And Data Handling
Disclose funding and any roles of sponsors. Share your extraction form and analysis code when possible. Note any contact with study authors for missing data. If you registered a protocol, add the record ID and any deviations with reasons.
Frequently Missed Moves That Save Time
Pilot Your Forms
Test screening rules and extraction items on a handful of studies. Tweak wording until two people make the same choices on the same set.
Prewrite The Results Skeleton
Before screening ends, draft the results outline with planned subsections and figure slots. This lets you drop numbers in once extraction finishes.
Adopt Consistent Language
Use the same terms for exposures, comparators, and outcomes across the text, tables, and figures. Align units and time points so readers can scan.
What To Hand In With The Manuscript
Most journals ask for a completed reporting checklist, a flow diagram, and the data extraction sheet. Some ask for the protocol and any code. Prepare these while you write so submission is smooth.
Helpful Standards Worth Bookmarking
The PRISMA 2020 checklist lists what to report, and the RoB 2 tool explains bias ratings for trials. Many journals request both.
When A Meta-Analysis Fits And When It Doesn’t
Pool results only when studies ask a similar question, measure outcomes in a compatible way, and report enough data to combine. Pick a random-effects model when clinical settings and methods vary. Check small-study effects with a funnel plot, then look for reasons they might appear. If pooling would blur clear differences, keep results separate and tell readers why.
Reference Management And Deduplication
Use software such as EndNote, Zotero, or Rayyan to import records from each database. Turn off smart features that change titles or author fields. After import, run a two-step de-dupe: first on DOI or trial ID, then on title plus year. Keep a backup of the raw export so you can retrace steps if counts shift during screening.
Plain Language Style That Still Feels Clinical
Short words beat long ones. Swap jargon for plain terms unless the audience expects the exact label. Use active voice for actions you took and past tense for what studies reported. Keep sentences under two lines on mobile. Add short lead-ins above busy figures so a reader knows what to look for before scanning numbers.
Final Checklist For Writers
• Clear PICO/PEO stated. • Protocol drafted and, when needed, registered. • All databases and dates documented. • Dual screening used when stakes are high. • Extraction form piloted. • Bias assessed with the right tool. • Synthesis matches design and data. • Reporting follows a checklist. • Limits and next steps stated with care.