What is a rapid review?
A rapid review is a form of knowledge synthesis that accelerates the systematic review process to meet a time-sensitive decision need — typically delivering results in 2 to 6 months rather than the 12 to 18 months a full systematic review demands. Rapid reviews achieve speed by simplifying, streamlining, or omitting specific steps of the systematic review pipeline: limiting databases, restricting by language or date, using single-reviewer screening with verification, extracting a narrower set of variables, and relying on narrative rather than meta-analytic synthesis. They are not "worse" systematic reviews; they are a distinct methodology for a distinct purpose.
The canonical methodological references are the Cochrane Rapid Reviews Methods Group interim guidance (Garritty et al., "Cochrane Rapid Reviews Methods Group offers evidence-informed guidance to conduct rapid reviews," Journal of Clinical Epidemiology, 2021) and the World Health Organization's Rapid Reviews to Strengthen Health Policy and Systems: A Practical Guide (Tricco, Langlois, and Straus, 2017). Both organizations converge on the same principle: transparency about the shortcuts taken is more important than following any single recipe.
Rapid reviews rose to prominence during the COVID-19 pandemic, when decision-makers needed weekly evidence updates on interventions, transmission, and public health measures. They are now established across health technology assessment (HTA), guideline development, and policy contexts.
When to use a rapid review
A rapid review is the right choice when:
- A policy or practice decision cannot wait. Guideline panels, ministries of health, and hospital administrators often need a defensible synthesis within weeks, not years.
- The evidence base is manageable. If there are hundreds of thousands of records, streamlining may not be enough — consider an umbrella review of existing systematic reviews instead.
- A systematic review would duplicate effort. If a similar review exists but is outdated, a rapid update may be more efficient than a full re-do.
- The question is focused. Rapid reviews work best with narrow, PICO-style questions. Broad or exploratory questions fit better with a scoping review.
- Stakeholder involvement is high. Rapid reviews often involve close collaboration with decision-makers to prioritize outcomes, refine the question, and interpret findings under uncertainty.
Contrast with a narrative review (interpretive, no protocol) and a systematic review (full rigor, longer timeline). A rapid review is the disciplined middle path.
Step-by-step process
The rapid review compresses the five-phase pipeline without abandoning its structure:
- Scoping and stakeholder engagement. Work with the commissioner to refine the question, confirm the timeline, and agree on the acceptable methodological shortcuts. Publish a brief protocol (OSF is common) even under tight deadlines.
- Streamlined search strategy. Typically 2–3 major databases (e.g., MEDLINE, Embase, and a topic-specific database) plus targeted grey literature. Date and language restrictions are acceptable but must be justified and reported. A librarian co-author remains highly valuable.
- Accelerated screening. Common shortcuts include single-reviewer title/abstract screening with a second reviewer verifying excluded records (or a sample), and dual full-text screening where feasible. Covidence and Rayyan both support these workflows.
- Focused data extraction and risk-of-bias assessment. Extract a minimal set of variables, often by a single reviewer with a second verifying. Use established tools (RoB 2, ROBINS-I, or JBI) but apply them to prioritized outcomes rather than every outcome reported.
- Synthesis and reporting. Narrative synthesis is the norm; meta-analysis is used when time and data permit. Report transparently — state every deviation from full systematic review methods and its likely impact on conclusions. PRISMA 2020 remains the reporting backbone.
Reporting standards
Rapid reviews should follow PRISMA 2020 and explicitly report each methodological shortcut under the Cochrane Rapid Reviews Methods Group guidance. The Cochrane guidance enumerates acceptable concessions (single-reviewer screening with verification, date/language limits, narrower databases) and requires that each be disclosed. The WHO's practical guide provides complementary templates. See the reporting standards overview.
Common pitfalls
- Undisclosed shortcuts. Readers need to know exactly what was simplified. A rapid review that looks like a systematic review without disclosing its concessions is misleading.
- Scope creep under deadline. Saying yes to new sub-questions mid-review guarantees missed deadlines. Lock scope in the protocol.
- Single-reviewer errors. Solo screening and extraction introduce bias. Always have a second reviewer verify a sample or all excluded records.
- Skipping risk-of-bias assessment. Speed does not excuse unappraised evidence. Apply a validated tool, even if to a narrower outcome set.
- Over-claiming certainty. Conclusions must reflect the simplified methods. Use GRADE or equivalent, and be explicit about where rapid methods reduce confidence.
Tools & templates
Use the Search Strategy Documentation Form (with shortcuts explicitly flagged), the PRISMA Flow Diagram Template, the Data Extraction Form Template trimmed to essential variables, and the Literature Review Matrix for narrative synthesis. All are available in the templates library.
Next steps
Rapid reviews live or die on disciplined scope. The fastest teams are not the ones that cut corners on the fly — they are the ones that agreed, in writing, which corners they would cut before they began. Lock the protocol in the first week, and keep every extracted study in a shared matrix so the team can see progress in real time. The Subthesis Literature Matrix gives your rapid review team a live, shared workspace that pays for itself in week one.