Umbrella review services

An umbrella review sits at the top of the evidence pyramid, and it earns that position only when the literature beneath it is already mature. The signal to commission one is simple: several systematic reviews and meta-analyses now exist on your broad question, often examining different interventions, outcomes, or populations, and a decision maker needs them read together rather than one at a time. Public health teams comparing many preventive strategies, clinicians weighing competing treatments for a condition, and guideline groups mapping a whole evidence base are the typical commissioners.

The design is the wrong choice when the underlying reviews are thin or absent. If only one or two reviews exist, or the existing reviews are out of date, a fresh systematic review or an update usually serves you better. We say so at the scoping stage rather than forcing an umbrella structure onto evidence that cannot support it. Where the topic is genuinely broad but under-reviewed, a scoping review is often the more honest first step, and we will point you there.

We build umbrella reviews on an established methodology rather than an ad hoc summary. The Joanna Briggs Institute guidance for umbrella reviews defines the sequence, from a registered protocol and a search for reviews through eligibility, appraisal, and synthesis. Reporting follows PRIOR, the Preferred Reporting Items for Overviews of Reviews, which was written specifically for reviews of reviews and asks for the things generic guidelines miss, such as how overlap was measured and how the certainty of the included reviews was handled.

1. 1

   Locate and select reviews

   We search for systematic reviews and meta-analyses on your question, screen them against review-level eligibility criteria, and record the selection in a PRISMA-style flow.

2. 2

   Appraise with AMSTAR 2

   Every included review is rated with AMSTAR 2, so its methodological quality and any critical flaws are visible before its findings are carried into the synthesis.

3. 3

   Map and quantify overlap

   We build a citation matrix of primary studies against reviews and compute the corrected covered area, so shared trials are not mistaken for independent evidence.

4. 4

   Re-grade and tabulate

   We re-assess certainty with GRADE where the source data allow and present results in a summary-of-reviews table that a reader can act on.

Overlap is the problem that separates an umbrella review from an ordinary summary. Because included reviews sit on the same body of literature, two reviews concluding the same thing may simply be citing the same trials, which is agreement by construction rather than replication. We make that visible by constructing a citation matrix that lists every primary study down one axis and every included review across the other, then calculating the corrected covered area, the standard metric for the proportion of study inclusions that are repeated. High-overlap clusters are reported openly, and concordant findings drawn from the same trials are described as such rather than presented as independent confirmation.

Where the original reviews report enough detail, we also re-grade the certainty of evidence with GRADE so the umbrella review carries a consistent confidence rating across outcomes, instead of inheriting a patchwork of different systems from the source reviews. The result is a synthesis a reader can trust, with its limitations stated plainly.

You get a complete, PRIOR-compliant umbrella review manuscript with the analysis that stands behind it. That means the review-level search and selection record, the AMSTAR 2 appraisal of each included review, the citation matrix and corrected covered area for overlap, the GRADE re-assessment where feasible, and a summary-of-reviews table that brings the findings into one view.

• A registered protocol with review-level eligibility criteria
• A documented search for systematic reviews and a PRISMA-style selection flow
• AMSTAR 2 appraisal of every included review, with critical flaws flagged
• A citation matrix and corrected covered area quantifying overlap of primary studies
• GRADE certainty re-assessment across outcomes where the source data allow
• A summary-of-reviews table and a PRIOR-compliant methods and results write-up

The two designs are easy to conflate and answer different questions. The table below shows where they diverge, so you can confirm an umbrella review is what your question actually needs before we scope it. If your topic has few or no existing reviews, our systematic review, meta-analysis, and scoping review services are the better fit, and we will say so rather than sell you the wrong design.

We quote a fixed fee per project, known before any work begins, rather than charging by the hour. What sits behind the number is the real analytical load: how many reviews are likely to be eligible, how broad the question is, whether overlap analysis will be straightforward or tangled across many shared trials, and how much of the writing you want us to draft. Send your question and any reviews you already know of, and a PhD methodologist will scope the work and return a fixed quote with no obligation to proceed.