A living systematic review continually looks for relevant new research and incorporates it promptly. “Living” describes a process, not a certainty rating. This guide helps readers establish what evidence a particular version actually includes. Cochrane Handbook, Chapter 22.
Three records to check
Our practical reading worksheet separates three records that a generic “updated” label can hide:
- Search coverage: the dates and sources actually searched.
- Incorporation status: which identified studies have been screened, judged eligible, appraised, and included in the synthesis.
- Published version: the dated report containing the estimates and conclusions you are reading.
PRISMA-LSR distinguishes review versions from status reports between versions. A status report can explain whether new studies are awaiting incorporation or living mode has ended. Check both before describing a review as current. PRISMA-LSR statement.
A fictional timeline
Suppose a review searches through March 31, completes screening on April 10, and publishes a new analysis on May 1. A second search runs through April 30, but its screening remains unfinished.
The May 1 publication is not automatically a synthesis of all eligible evidence through April 30. Its publication date and completed evidence coverage answer different questions. This invented example is a reading exercise, not the history of an actual review.
For your notes, a useful formulation is: “Version published May 1; completed search coverage through March 31; April search results still being assessed.” If the report does not supply a date or status, mark it unavailable rather than guessing.
When living mode helps
Cochrane describes living reviews as especially useful for important questions with low existing certainty and an expectation of further research. The protocol should explain search methods and anticipated update frequency. Searching alone is not a completed evidence synthesis. Cochrane living-review guidance.
Read what changed
A review update can incorporate new outcomes from an existing study, corrections, or retractions as well as newly identified studies. It may also alter scope or methods. Cochrane recommends reporting and explaining such changes; a new study count alone cannot describe their effect on the conclusion. Cochrane guidance on updating reviews.
Our suggested comparison note records the old and new question, included studies, estimated effect, uncertainty, certainty judgment, and stated reason for each change. Keep the two versions side by side. Do not attach the latest publication date to an estimate copied from an older analysis.
Update schedules and responsibilities
PRISMA-LSR, published in 2024, supplements PRISMA 2020. It asks authors to report living-mode schedules or triggers, changes to methods and results, and contributors’ roles for each version. Between versions, status information should make ongoing work or retirement visible. These are transparency requirements, not a guarantee of high-certainty findings. Official extension; checklist and explanation.
Retirement is not always a scientific conclusion
Murad and colleagues proposed retirement triggers including sufficiently conclusive evidence, reduced relevance, no anticipated new studies, or unavailable resources. These are proposed considerations rather than a universal stopping rule. The authors favor judging conclusiveness through evidence certainty rather than statistical significance alone. Primary methods paper.
The practical implication is important: a review retired because funding ended is not thereby conclusive. Record the reason for retirement separately from the confidence warranted by its findings.
Further reading and scope
Start with systematic reviews and meta-analysis for synthesis fundamentals. Read risk of bias and evidence certainty to understand why updating and confidence are separate issues, or return to the evidence guides.
This page explains living reviews; it is not itself a living systematic review or a promise of continuous surveillance of every study in this library.
About this guide
Sources checked October 1, 2026. Prepared with AI assistance and source checking; no independent evidence-synthesis or clinical review is claimed. This educational guide is not medical advice or proof of a product’s safety, effectiveness, or identity. Send corrections through the contact page.