Open with the problem, note what’s known and unknown, state your question and scope, then end with how the review will help care.
Writing the opening of a medical review is a craft. The first few paragraphs set the context, answer why the topic matters to care, and prime readers for how you will synthesize evidence. The guide below gives you a repeatable plan that fits journal standards while staying clear, concise, and readable.
What editors and readers look for
Editors want clarity on the clinical or public health problem, a short map of prior work, a crisp gap statement, and a precise aim. Readers want the same, with plain language, transparent scope, and a promise that the review will save them time. Keep the opening tight, fact-checked, and free of hype.
Core building blocks at a glance
| Building block | What it answers | Writer prompts |
|---|---|---|
| Problem | What clinical or policy pain point is at stake? | Who is affected, where, and how big is the burden? |
| Context | What is already known? | Landmark trials, prior reviews, guidelines, controversies. |
| Gap | What is unclear or conflicting? | Outcomes not measured, subgroups ignored, methods outdated. |
| Aim | What will this review do? | State the main question in one sentence. |
| Scope | What you will include and exclude. | Population, interventions, comparators, outcomes, settings, time range. |
| Signal | Why now? | New therapies, safety alerts, policy shifts, new data. |
| Roadmap | How the review is organized. | One line on sections or logic of synthesis. |
Writing an introduction for a medical literature review: a repeatable flow
Use the flow below to move from broad context to a sharp aim. Each step can be one short paragraph; in fast-moving topics, two. Cite sources sparingly and prefer recent, high-quality evidence.
Start with the problem
Lead with a clinical or population pain point. Name the condition, who carries the burden, and the impact on outcomes or resources. One to three statistics are enough. If you cite rates, pair them with absolute numbers. Use current data.
Outline what is known
Summarize the state of the field in a few lines. Name core mechanisms, standard care, and any major shifts. Point to the most authoritative sources rather than many small ones.
Surface the gap
Spell out the uncertainty. It might be heterogeneity in study designs, missing subgroups, short follow-up, poor outcome reporting, or bias risk. Make the gap concrete and testable.
State the aim
Write one sentence that states the purpose of the review. Use active voice and clear verbs such as compare, map, summarize, or evaluate. Place this sentence near the end of the opening section.
Mark the scope
Define the boundaries in plain terms. List the population, interventions or exposures, comparators, outcomes, settings, and time window. If you use PICO, spell it out for non-specialists.
Add a signal for timeliness
Give a short reason this review adds value now, such as a new therapy, a new safety signal, a policy change, or recent high-quality trials.
Offer a brief roadmap
Close the section by telling readers how the paper is structured or how the synthesis proceeds.
How to write the introduction for a medical literature review: sample outline
Paragraph 1 — problem and burden
Name the condition and scale. Include one global or national statistic and one setting-specific figure. Avoid stacking citations; pick the best sources.
Paragraph 2 — what we know
Summarize standard care, key mechanisms, and any milestone trials or policies. Keep it to a few lines.
Paragraph 3 — gap
Describe the missing piece that blocks clear guidance or action. Keep the claim narrow and checkable.
Paragraph 4 — aim
State the purpose in one line. Use strong, plain verbs and avoid hype.
Paragraph 5 — scope
Define inclusion signals: population, interventions or exposures, comparators, outcomes, settings, time span. Mention language limits only if relevant to readers.
Paragraph 6 — roadmap
Point to the structure of the paper or the logic of the synthesis. One line is enough.
Use trusted standards when you cite and frame
When you mention reporting or selection choices in the opening, link to recognized guides. For systematic reviews, the PRISMA 2020 checklist is the baseline. For journal style and section order, the ICMJE Recommendations set common expectations. To choose consistent terms, browse the MeSH Browser so definitions in your opening align with indexing.
Write data paragraphs that land
Pick statistics that match the aim. If your review centers on treatment effects, quote outcome rates and effect sizes, not only prevalence. Prefer recent surveillance or registry data to small single-center reports. Give the time frame and setting for every number. Where estimates vary, present a range and the reason for spread, such as sampling, definitions, or follow-up length.
Make scope and definitions unambiguous
Spell out population, interventions or exposures, comparators, outcomes, and settings in one compact sentence. Define acronyms on first use. If a term has multiple meanings, give the one you use and cite a widely accepted source. If you include both adult and pediatric data, say so here. If you exclude preprints or non-peer-reviewed material, say it here as well.
Tone, tense, and style that work in medicine
Use present tense for accepted facts and past tense for completed studies. Keep sentences short and verbs active. Avoid value-laden adjectives. Replace jargon with plain language. Place citations after the first clause so the sentence reads cleanly. Keep direct quotes out of the opening unless a guideline statement is central to the topic.
Tailor the opening by review type
Systematic
Keep the opening lean. Name the clinical question, the gap that motivates a new synthesis, and the PICO. Point to protocol registration if it exists. Avoid long method detail; save it for the next section.
Narrative
Open with the problem and why a narrative lens adds value, such as theory or mechanisms. Use clear signposting to avoid drift. A short note on how sources were chosen helps trust.
Scoping
State that the goal is mapping concepts, sources, and gaps. Say why mapping is needed before quantitative pooling. Clarify boundaries to keep expectations aligned.
Umbrella
Flag that the unit of analysis is published reviews. Explain why an overview is needed, such as overlapping reviews or discordant conclusions. Define inclusion criteria for the reviews you will summarize.
Rapid
State the decision need and the time constraint that shaped a streamlined approach. List any preplanned shortcuts in one line so readers understand trade-offs early.
Plan citations with restraint
Use one or two high-quality sources per point. Prefer consensus statements, large registries, and well-designed trials. If you cite a prior review, say how your scope differs. Avoid chains of secondary citations; track back to the earliest reliable source.
Length, order, and journal fit
Many journals expect a short opening that stays under a page in standard formatting. A practical range is two to six paragraphs, with the aim and scope landing by the end of paragraph four. Keep tables, figures, and long definitions out of the opening so readers reach the purpose line quickly.
Common pitfalls and quick fixes
| Pitfall | Fix | Quick check |
|---|---|---|
| Vague gap statement | Link the gap to a decision, outcome, or subgroup. | Can a reviewer test the claim with the cited studies? |
| Overloaded citations | Pick two or three gold-standard sources. | Remove duplicates that say the same thing. |
| Scope hidden in methods | Add a one-line PICO in the opening. | Would a new reader know what is inside or outside? |
| Jargon and acronyms | Define on first mention and prefer plain terms. | Would a first-year resident follow every line? |
| No roadmap | Add one sentence that previews the structure. | Can a skim reader tell where to jump? |
Quality checks that map to the intro
For narrative work, ask whether the opening justifies the topic, states a focused aim, and describes source selection in brief. For systematic work, confirm that the question and scope align with later methods and that the opening does not oversell outcomes the body cannot support. In both, keep claims modest and traceable.
Mini workflow to draft faster
- Dump facts for the problem paragraph into a scratch file.
- Pick two anchor sources for each claim and drop the rest.
- Write a one-line aim and a one-line scope before any prose.
- Shape the opening into six short paragraphs using the outline above.
- Swap jargon for plain terms and align labels with MeSH.
- Add links to the PRISMA 2020 checklist or the journal’s guide where helpful.
- Read aloud and trim any sentence that takes effort to parse.
Ten-point pre-submission checklist
- The opening names the condition and burden with current numbers.
- The context paragraph cites the best sources and avoids citation stacks.
- The gap is concrete, narrow, and testable.
- The aim is one sentence in active voice.
- Scope signals (population, exposures or interventions, comparators, outcomes, settings, time span) appear in the opening.
- Key terms match accepted MeSH labels where possible.
- Language defines acronyms at first use and avoids jargon.
- Claims about novelty or timeliness are modest and backed by a source.
- A one-line roadmap closes the section.
- Links to PRISMA or journal guidance appear where they help readers.
Short paragraph templates you can adapt
Narrative review
Condition X affects [group] and leads to [outcomes]. Standard care includes [treatment] and [support]. Recent studies suggest [trend], yet evidence for [subgroup/outcome] remains limited. This review summarizes current knowledge on [topic] and clarifies [gap] to guide practice and research.
Systematic review
Condition X causes a large burden in [setting]. Prior trials of [intervention] report mixed effects on [outcome]. Uncertainty remains for [population/subgroup] and for [time horizon]. We aim to compare the effects of [intervention] versus [comparator] on [outcomes] in [population], using prespecified criteria and transparent methods.
Scoping review
Interest in [topic] has grown with the spread of [innovation/policy]. Evidence spans varied designs and measures, which makes synthesis hard. This review maps concepts, sources, and gaps across [population/setting] to guide future systematic work.
Rapid review
Clinicians need timely guidance on [topic] due to [event/policy shift]. We conducted a streamlined review of [population/intervention] with focused searches and abbreviated screening to summarize available evidence for near-term decisions.
Phrasing toolbox for clean, direct openings
- Condition X is a major cause of [outcome] in [population].
- Current care relies on [intervention], yet results vary across [subgroup/setting].
- Evidence for [topic] is mixed due to differences in [design/outcome length/definitions].
- We set out to compare [intervention] with [comparator] for [outcome] in [population].
- In this review we include studies from [years] and [settings], focusing on [outcomes].
- We use definitions aligned with MeSH to keep terms consistent.
When to mention ethics, conflicts, and funding in the opening
If a conflict of interest or funding source directly relates to the review’s aim or data access, include one clear sentence in the opening and expand in the disclosures section. Keep the tone factual and use journal-approved wording.
Polish the opening like an abstract
Trim every extra word. Convert long nouns into verbs. Replace stacked clauses with two short sentences. Read the opening aloud and time it; one to two minutes signals you are in range. Ask a colleague from another specialty to read it; if they can follow every line, you are ready to move on.