GUIDE
Scoping Review vs Systematic Review: Which One Do You Need?
Choosing the wrong one isn’t a formality — it changes your question, your protocol, your reporting guideline, and whether critical appraisal is even expected.
Published October 10, 2026
Both involve a systematic search and a documented selection process. That surface similarity is exactly why teams pick the wrong one — the real difference is in the question each is built to answer.
Start with a free protocol template“Should this be a scoping review or a systematic review?” is a question worth answering before you write a word of the protocol, not partway through screening. Both use a systematic, documented search. Both can involve dual screening and PRISMA-style reporting. Where they diverge is purpose: one answers a specific question; the other maps a body of literature.
What a systematic review is for
A systematic review answers a focused question — usually structured as PICO (Population, Intervention, Comparator, Outcome) — with a comprehensive, critically appraised synthesis of the evidence. Every included study gets a risk-of-bias assessment. The result is often, though not always, a pooled effect estimate. See systematic review vs meta-analysis for how that pooling step fits in.
What a scoping review is for
A scoping review maps the extent, range, and nature of research activity on a broader topic. Arksey and O’Malley first set out the methodology in 2005; Levac, Colquhoun, and O’Brien advanced it in 2010; the Joanna Briggs Institute (JBI) has since published detailed methodological guidance. Scoping reviews are used to:
- Map what has been studied on a topic, and identify gaps worth a future systematic review.
- Clarify how key concepts or terms are defined and used across a body of literature.
- Examine how research on a topic is conducted - designs, populations, and methods used.
- Scope whether a full systematic review is even feasible before committing to one.
Instead of PICO, scoping reviews typically use JBI’s PCC framework - Population, Concept, Context - which fits a broader, more exploratory question than PICO is built for.
Side by side
| Systematic review | Scoping review | |
|---|---|---|
| Question type | Focused, usually PICO-structured | Broad, exploratory - usually PCC-structured |
| Typical purpose | Answer a specific question about effectiveness or association | Map the breadth of a field; identify gaps or clarify concepts |
| Risk-of-bias assessment | Required for every included study | Not typically required or expected |
| Quantitative synthesis | Often, when studies are comparable enough | Essentially never - included studies are usually too heterogeneous |
| Study designs included | Usually constrained by eligibility criteria (e.g. RCTs only) | Often deliberately broad - any design, sometimes grey literature |
| Reporting guideline | PRISMA 2020 | PRISMA-ScR (Tricco et al., 2018) |
| Typical output | A synthesis, often with a pooled estimate | A descriptive or tabular map of the literature |
Deciding which one your project actually is
Munn et al. (2018) frame the decision around what you’re actually trying to find out:
- Choose a systematic review when you have a specific, answerable question and enough comparable studies exist to critically appraise and synthesize them - whether or not that synthesis ends up quantitative.
- Choose a scoping review when the question is broader than PICO can hold, you need to know what’s even out there before committing to a narrower question, or the point is mapping concepts and gaps rather than appraising evidence quality.
- A scoping review can be the step before a systematic review - used to confirm there’s enough comparable evidence, and narrow a broad topic into an answerable PICO question, before registering the systematic review itself.
Decide this at the protocol stage. A review that starts as “systematic” but turns out to need a scoping approach partway through screening — because the studies are too varied to appraise consistently — is a sign the question was framed too broadly from the start.
References
Arksey H, O’Malley L. Scoping studies: towards a methodological framework. International Journal of Social Research Methodology. 2005;8(1):19-32. doi.org/10.1080/1364557032000119616. Levac D, Colquhoun H, O’Brien KK. Scoping studies: advancing the methodology. Implementation Science. 2010;5:69. doi.org/10.1186/1748-5908-5-69. Tricco AC, Lillie E, Zarin W, et al. PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation. Annals of Internal Medicine. 2018;169(7):467-473. doi.org/10.7326/M18-0850. Munn Z, Peters MDJ, Stern C, et al. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Medical Research Methodology. 2018;18:143. doi.org/10.1186/s12874-018-0611-x.
Continue your review workflow
- Not sure if you need a meta-analysis too? Read systematic review vs meta-analysis first.
- Once you’ve settled on a systematic review, start with a free protocol template and define PICO before screening begins.
- Run title and abstract screening against your eligibility criteria, then document the process with a PRISMA 2020 flow diagram.
- Start a free EvidenceFlow review to keep screening, extraction, and reporting on one project.
Know which review you’re running? Start the protocol.
Define your question, your criteria, and your synthesis plan before screening starts.
EvidenceFlow’s screening, extraction, and PRISMA reporting workflow fits a systematic review’s structured process - including the risk-of-bias and synthesis steps a scoping review typically skips.
FAQ
What's the main difference between a scoping review and a systematic review?
A systematic review answers a focused, usually PICO-structured question with a critically appraised, often quantitatively synthesized set of studies. A scoping review maps the extent and nature of research on a broader topic - what's been studied, what hasn't, and what terms and methods researchers use - without requiring critical appraisal or a pooled result.
Do scoping reviews need a protocol or registration?
A protocol is still considered good practice and can be registered (PROSPERO accepts some scoping review protocols; the Open Science Framework is commonly used too), but it isn't universally required the way systematic review registration increasingly is. Check your target journal and funder's expectations.
Do scoping reviews assess risk of bias?
Usually not, and this is one of the clearest practical differences. Because scoping reviews often include very heterogeneous study designs (and sometimes grey literature) specifically to map breadth, applying one formal risk-of-bias tool across all of them is often not meaningful. Some scoping reviews do include a basic quality appraisal - state explicitly whether you did or didn't, and why.
Can a scoping review include a meta-analysis?
Essentially never, and if yours does, it's probably not a scoping review. The included studies in a scoping review are typically too heterogeneous in design and question for pooling to be meaningful - that heterogeneity is often exactly what a scoping review exists to document.
Which reporting guideline do I use?
PRISMA-ScR (Tricco et al., 2018) for a scoping review; PRISMA 2020 for a systematic review. They share structure but PRISMA-ScR drops items that assume critical appraisal and quantitative synthesis, and uses PCC (Population, Concept, Context) instead of PICO for framing the question.