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Umbrella Review and Overview of Reviews for Researchers and Evidence Teams
Pubrica’s subject matter experts and information specialists conduct umbrella reviews, which synthesise existing systematic reviews rather than primary studies, for guideline groups, HTA and policy teams, societies, researchers and medical affairs teams. An umbrella review is the appropriate method when a field already has several systematic reviews and it is unclear whether they agree. You receive a registered protocol, a recorded search, AMSTAR 2 and ROBIS appraisals of every included review, a primary-study overlap matrix with corrected covered area, and a manuscript reported under PRISMA 2020.
- Overlap measured, not assumed — the primary-study matrix built and corrected covered area reported, showing how much of the apparent evidence comes from the same trials counted more than once
- Every included review appraised with AMSTAR 2 and ROBIS, because one rates the review’s methodological quality and the other the risk of bias in how it was conducted
- Disagreement explained rather than averaged — we identify why reviews reached different conclusions instead of averaging their results
- JBI methodology, reported under PRISMA 2020, with the overlap matrix and appraisal table delivered as working files
- Clear advice when another method is needed — where the existing reviews are too few or too weak, we advise you before quoting
Overlap quantified as corrected covered areaIncluded
AMSTAR 2 and ROBIS on every included reviewIncluded
Overlap matrix and appraisal table deliveredIncluded
Disagreement between reviews explainedIncluded
Re-analysis of the primary trialsRequires a systematic review
Reviews → appraised → overlap measured → synthesised → manuscript
- Corrected covered area reported
- AMSTAR 2 and ROBIS applied
- JBI methodology
- PRISMA 2020 reporting
- Overlap matrix delivered
Service Scope
Four Umbrella Review Service Areas, Available Individually
Pubrica provides each stage of an umbrella review as a separate service, so you can outsource the complete review or only the stage you need, such as the overlap analysis and appraisal.
Who we serve
Researchers and Organisations We Support with Umbrella Reviews
We support guideline developers, societies, HTA and policy teams, researchers and medical affairs teams who need a field-level view of existing systematic reviews.
Deliverables
What Every Umbrella Review Includes
Every umbrella review assesses the included reviews themselves, rather than listing their conclusions side by side.
From the overlap matrixEleven systematic reviews were included, covering 214 primary studies.Eleven reviews were included, covering 214 study records but only 63 distinct primary trials. Corrected covered area 18%, which is high overlap — four of the eleven reviews share more than three quarters of their included trials.
From the appraisalEleven reviews were included and synthesised.Of eleven included reviews, three were rated critically low on AMSTAR 2 — no protocol, no list of excluded studies, and no assessment of risk of bias in the primary trials. Their conclusions are reported and are not pooled with the rest.
From the synthesisFindings were mixed across the included reviews.Two reviews found benefit and two did not. The difference is entirely the 2023 multicentre trial: the two null reviews had search dates before it published. It is not a genuine disagreement in the evidence.
From the scoping callThree reviews exist, so an umbrella review is possible.Three reviews exist. Two are critically low, and the third covers a narrower population than your question. An umbrella review here would inherit those problems. A systematic review of the primary studies costs more, and it answers the question you are asking.
These samples are illustrative and anonymised. Hover over a sample to replay it.
Methodology
How Our Umbrella Review Process Works
We complete the appraisal and the overlap matrix before the synthesis, because both affect which conclusions the synthesis can support.
Question, protocol and search for reviews
We frame the question, register the protocol and search for systematic reviews rather than primary studies, which requires different filters and databases.
Appraise every included review
Two reviewers apply AMSTAR 2 and ROBIS to each review independently and name the critical weaknesses rather than reducing them to a total score.
Build the overlap matrix
We map every primary study in every included review and calculate corrected covered area, so the synthesis reflects the amount of independent evidence available.
Synthesise and report
We synthesise the findings, explain any disagreement, report under PRISMA 2020 and deliver the overlap matrix and appraisal table as working files with the manuscript.
Responsible Use of AI
Responsible Use of AI in Umbrella Reviews
An umbrella review is already one step removed from the primary studies, so we do not add unaudited automation to the reading of the included reviews.
Why We Do Not Publish an AI Accuracy Figure
Accuracy figures for AI tools are usually reported by the companies that sell them.
For the same reason, Pubrica does not quote an accuracy figure of its own, as it would carry the same conflict of interest. Instead, we tell you which tool was used on your project, at which stage, and what our reviewers changed after it.
Our experts
Your Umbrella Review Team
Your project is handled by a named team of subject specialists who stay with it from scoping to delivery. Your project coordinator introduces each team member before work begins.
Designs and runs the literature search, writing the strategy line by line for each database and delivering it dated and fully reproducible.
Defines the question and scope and checks that every conclusion is supported by the evidence. Matched to your topic, the subject expert advises you directly when the evidence does not support an intended conclusion.
Reviews the work independently of the first reviewer and reconciles the two, which catches transcription errors. Every disagreement is logged and adjudicated.
Leads the statistical analysis, confirms before analysis begins whether the data can answer the question, and delivers the code so the analysis can be reproduced independently.
Packages
Umbrella Review Service Packages
The cost of an umbrella review depends on the number of reviews included and the degree of overlap between them, rather than on record volume as in a systematic review.
Overlap and appraisal only
Teams writing the synthesis themselves
Quoted per projectBased on the number of reviews included
Delivery By scope
- ✓Search for systematic reviews, recorded per database
- ✓AMSTAR 2 and ROBIS on every included review
- ✓Primary-study overlap matrix built
- ✓Corrected covered area calculated and reported
- ✓Working files handed over
Add later: the full synthesis and manuscript.
Deliverables Request a quoteFull umbrella review
Authors and evidence teams publishing the overview
Quoted per projectBased on the number of reviews included
Delivery By scope
- ✓Everything in Appraisal
- ✓Protocol registered before the search runs
- ✓Synthesis with disagreement explained rather than averaged
- ✓Full manuscript reported under PRISMA 2020
- ✓Journal formatting and response to reviewer comments
Add later: a systematic review of the primary studies where the reviews will not carry the question.
Deliverables Request a quoteBoth packages are quoted individually, because two umbrella reviews with the same number of included reviews can differ in cost by a factor of three once the overlap matrix is built. The scoping search is free, and the quotation is confirmed in writing before work begins.
Benefits
Benefits of a Pubrica Umbrella Review
The main benefits of commissioning an umbrella review from Pubrica.
Quality Assurance
Our Service Commitments and Limitations
Our service terms are set out in full below so you can review them before you commit.
The Pubrica guarantee
Revision Support Until Agreed Requirements Are Met
We continue revising the work until it meets the requirements agreed within the scope. Rather than offering a refund, which would end the engagement with the work incomplete, we keep working until the agreed requirements are met.
01
Unlimited revisions within the agreed scope
There is no limit on the number or timing of revision rounds within the agreed scope. If the work does not meet the agreed requirements, we revise it. Work outside the agreed scope is quoted separately, and we confirm which applies before any work starts.
02
Corrections at Our Cost
If an error in our analysis or writing needs correcting, we correct it free of charge.
03
Delivered on the date agreed
We quote a delivery date we can meet and work to it. If a milestone is at risk, we inform you in advance.
04
Mutual NDA on request
We sign a mutual non-disclosure agreement before you share any material, at no cost, and we can sign your organisation’s NDA instead of ours.
05
You Retain Final Decisions
We give clear methodological advice and tell you when we disagree with a proposed approach. You make the final decision on everything published in your name.
Average client rating
From 3,000 responses to Pubrica’s post-delivery survey, sent to every client at handover between January 2024 and June 2026. This figure comes from our own records rather than from an external rating service.
Limitations of Our Service We cannot guarantee decisions made by others, such as an editor’s decision, a funding panel’s outcome or a regulator’s assessment. Within the agreed scope, we commit to the work itself: completed to the standards named on this page, delivered on the agreed date and corrected at our cost if we made an error.
FAQs
Umbrella Review FAQs
If your question is not answered here, please ask an expert. No quote is required.
A systematic review synthesises primary studies. An umbrella review synthesises systematic reviews. The method is the same in spirit — a protocol, a recorded search, dual screening, appraisal — but the unit of analysis is a review rather than a trial.
This is why overlap matters in an umbrella review: two reviews can share most of their included trials, so counting both as independent evidence overstates the evidence available.
It is the standard measure of how much the included reviews overlap — how many of the primary studies appear in more than one of them. Low overlap means the reviews are largely independent. High overlap means much of the apparent evidence is the same trials counted again.
It helps determine whether an umbrella review is worthwhile. Above roughly 15%, the synthesis must account for the overlap, and we report the figure so that readers do not assume the reviews are independent.
Usually four or more of adequate quality. With two or three, or where most are rated critically low on AMSTAR 2, an umbrella review inherits their weaknesses and adds little value.
We tell you which applies during the free scoping search, before you commit, and advise you if a systematic review of the primary studies is needed instead.
No. That is a systematic review, and it is a different piece of work with a different price. An umbrella review works at the level of the reviews.
Where the appraisal shows that the existing reviews cannot answer your question, we quote for a systematic review instead of an umbrella review.
Related services
Related Research Services
Services that complement an umbrella review, or replace it where existing reviews are insufficient.
1IF EXISTING REVIEWS ARE INSUFFICIENTreview the primary studies
Systematic reviewOf the primary trials, from protocol onwards. Meta-analysisWhere studies are alike enough to pool.2IF THE FIELD IS UNMAPPEDmap it first
Scoping reviewWhat exists and where it stops. Evidence gap mapThe gaps, visually, for a portfolio.3IF THE REVIEW MUST STAY CURRENTregular updates
Living systematic reviewUpdated on a stated schedule. Rapid & targeted reviewSystematic methods with declared shortcuts.Request a Free Umbrella Review Feasibility Assessment
We assess feasibility free of charge within two business days, including whether a systematic review would answer your question better.