Yes, using a systematic review within a medical review is acceptable when you cite it transparently and explain how you used its methods and findings.
Writers ask this a lot: can an existing review sit inside a broader medical write-up and still pass peer and editorial checks? Short answer—yes. You can draw on a previous synthesis to anchor scope, compare conclusions, or update evidence. Clarity wins. Say what the included review covers, how you judged its quality, and where you added value—new search, fresh outcomes, or clinical context. That mix helps readers trust what they’re reading and lets editors see the work you did.
Where A Systematic Synthesis Fits
Think of the evidence base as layers. Primary studies sit at the base. Above that come structured syntheses. Your narrative sits on top, guiding the reader through questions, comparisons, and takeaways. In that middle tier, a previous synthesis can be a workhorse—if you show your method and mark the limits.
| Review Type | Best Use | Common Reporting |
|---|---|---|
| Systematic Review | Answer a focused clinical or policy question with preset criteria | PRISMA 2020 |
| Meta-Analysis | Pool compatible effect sizes to estimate a summary effect | PRISMA 2020 |
| Overview Of Reviews (Umbrella) | Synthesize findings from multiple syntheses on a broad topic | Cochrane Handbook Ch. V |
| Scoping Review | Map concepts, outcomes, and gaps without effect pooling | PRISMA-ScR |
| Rapid Review | Time-boxed answers for practice or policy with streamlined steps | PRISMA-2020 (adapted) |
Using An Existing Synthesis In Your Health Review — Rules That Keep Editors Happy
This section lays out a clean process. It keeps your write-up tight, fair, and transparent across journals.
State Your Intent Up Front
Say why you relied on an existing synthesis. Maybe the question was answered last year and you want to place new trials against that baseline. Maybe you need an “evidence map” before narrowing. Spell out that aim in the first page so readers know what to expect.
Screen For Suitability
Not every synthesis fits. Check topic match, inclusion window, and methods. If the PICO lines up and the search is current, you’re in good shape. If the fit is partial, say what pieces you will keep and what you will redo.
Appraise The Methods
Use a tool like AMSTAR 2 or ROBIS to judge conduct and bias. Report the domains you checked and the verdict. If the methods look shaky, treat the findings as background and lean on primary studies instead.
Manage Overlap
Two syntheses often share the same trials. Note it and prevent double counting. If you pool numbers, extract at the study level or select one source per trial using a rule (newer, broader, or better methods).
Update Where It Matters
New trials since the last search can change the picture. Run a top-up search, add the new data, and say how the new signal compares to the older estimate. If the change is large, show a small table or figure.
Keep Reporting Transparent
Follow a checklist that readers know. The PRISMA 2020 standard sets the bar for items such as eligibility, search strings, and flow diagrams. If your piece is an umbrella-style write-up, follow the Cochrane overview chapter for selection, overlap checks, and certainty grading.
Link to the public standards where readers can verify items and flow fields: the PRISMA 2020 checklist and the Cochrane overview guidance. These keep your write-up consistent and save edit rounds.
When Leaning On A Prior Synthesis Works Best
There are clear use-cases where a published synthesis adds speed and clarity without cutting corners.
Complex Topics With Many Comparators
When a topic spawns dozens of regimens, a published synthesis can pre-group trials and outcomes. That frees your space for clinical nuance and new data.
Practice Questions That Need A Wide Lens
Prevention programs, rehab bundles, and service models span diverse designs. An overview-style approach that draws from multiple syntheses can show patterns across settings while still naming the limits.
Updates On A Known Question
When the last full search ran 12–24 months ago, a focused update is efficient. Keep the older methods, add new studies, report any shift in effect, and state the new certainty.
When It Doesn’t Fit
Sometimes the topic or the source doesn’t work. Walk away from a prior synthesis when the question has changed meaningfully, the inclusion rules clash with your scope, or the methods fail basic checks. In those cases, either redo the synthesis from scratch or present a narrative built on primary studies with transparent limits.
Quality Checks You Should Show
Editors and reviewers look for proof of care. Here’s what to show in plain view. Keep each item easy to find so a reader can audit your method without hunting through appendices.
Clear Eligibility And Search
Describe criteria, databases, dates, and languages. If you reuse search strings from the source review, say so and show any tweaks.
Risk Of Bias And Certainty
Report risk-of-bias judgements for new trials you added. For the included synthesis, show the critical domains from AMSTAR 2 or the signalling questions from ROBIS. Wrap up with a certainty statement per outcome.
Handling Conflicts Between Sources
Different syntheses can disagree. When that happens, compare inclusion rules, outcome timing, and models. Then explain which set you trusted and why.
Common Missteps To Avoid
- Copying conclusions without checking eligibility and bias.
- Double counting trials when multiple syntheses include the same study.
- Calling a narrative summary “systematic” without a methods section.
- Using one old synthesis to make fresh practice claims without an update search.
- Stacking many low-quality syntheses instead of one or two solid ones.
Practical Workflow You Can Reuse
This is a repeatable set of steps. It works for journal submissions and for internal briefs.
Step 1 — Define Scope And Role
Write one line that states the PICO and how the existing synthesis will be used: as context, as the main evidence stream, or as a baseline for an update.
Step 2 — Find Candidate Syntheses
Search MEDLINE and Embase with a filter for syntheses. Add hand-searching from references and trial registries for new studies. Keep a small log so your selections are traceable.
Step 3 — Appraise Quality
Run AMSTAR 2 or ROBIS. Mark critical domains: protocol, search, duplicate screening, list of excluded studies, and risk-of-bias handling. Flag any concerns early.
Step 4 — Map Overlap
Create a matrix of included trials across candidate syntheses. Identify duplicates. Choose a main source for each trial or extract directly from the trial report.
Step 5 — Update The Evidence
Top-up the search to the present. Add new outcomes if needed. If pooling is feasible, run a meta-analysis with the expanded set and compare with the older estimate.
Step 6 — Write With Transparency
State the role of the prior synthesis in Methods. In Results, separate what came from the source and what you added. In the section on meaning for care, explain any change in effect or certainty and what it means for practice.
Mini-Templates You Can Copy
Use these short snippets to speed up drafting. Tweak wording to fit your journal.
Methods — Using A Prior Synthesis
“We based the initial evidence set on a prior structured synthesis (search through Month Year; PROSPERO ID if listed). We checked scope against our PICO, appraised conduct with AMSTAR 2, mapped primary-study overlap, and ran an update search in Database(s) through Month Year. New trials were screened in duplicate and risk-of-bias was assessed with Tool X.”
Results — What Was Reused And What Was New
“From the prior synthesis we retained N trials and M outcomes. The update search found K new trials. The pooled effect moved from Y to Z. Certainty by outcome is shown below.”
What The Shift Means For Care
“The added trials increased precision and shifted the point estimate toward benefit. Residual inconsistency stems from dosing schedules. Future research should clarify subgroup effects by baseline risk.”
Ethics, Authorship, And Fair Credit
Credit the original authors in text and reference list. If you reused data extraction or risk-of-bias tables, say so and cite. Follow journal authorship rules. Many outlets look to the ICMJE page for manuscript guidance on transparency and contributor roles.
Checklist For Reusing A Prior Synthesis
| Step | Action | Proof To Show |
|---|---|---|
| Fit | Confirm PICO match and time window | Table of scope vs. source |
| Quality | Run AMSTAR 2 or ROBIS | Domain ratings |
| Overlap | Map trials across sources | Matrix or list |
| Update | Top-up search to current month | Flow diagram |
| Bias | Judge risk for new trials | RoB table |
| Certainty | Grade by outcome if pooling | Summary of findings |
| Write-Up | Separate reused vs. new material | Methods and Results labels |
Editor-Friendly Finishing Touches
For reporting polish, match your journal’s article type in schema (Article or Review) through your CMS or plugin, keep the canonical URL unique, and avoid heavy hero images that push text down the first screen. On mobile, test that tables fit within the content width and that row labels are short enough to prevent sideways scrolling.
Before you send, do a quick pass for the basics: one clear question, transparent methods, and a short section that tells readers what changed after your update. Keep figures light so the first screen loads fast. Add descriptive alt text to images. Keep a single visible date on the page if your theme prints dates.
Takeaway For Authors
Yes—you can rely on a prior structured synthesis inside a medical write-up. Show your work: fit, quality, overlap, an update search, and clear labels for what was reused and what was new. Link to public standards, keep methods tight, and your piece will read clean and pass editorial checks.