Guide
Types of literature review
There are many types of literature review, from flexible narrative surveys to exhaustive systematic reviews and meta-analyses, each suited to a different question, level of rigour and timeframe.
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Why the type matters
Choosing a review type is one of the first decisions in evidence synthesis, because it sets how comprehensive your search must be, how formal your appraisal is, and what kind of answer you can claim. A focused effectiveness question demands a systematic review; a broad "what is out there?" question calls for a scoping review; a fast policy decision may justify a rapid review. Picking the wrong type wastes effort or overstates the strength of your conclusions. The labels are not always used consistently in the literature, so it helps to define your method by what you actually do — search, screen, appraise, synthesise — rather than by the name alone.
The major review types compared
The table below contrasts the most common types by aim, search approach, formal appraisal and relative effort. A narrative (or traditional) review surveys a topic selectively and flexibly. A systematic review answers a tightly defined question with an exhaustive, pre-specified and reproducible protocol, usually reported against PRISMA 2020. A scoping review maps the extent, range and nature of evidence on a broad topic, often to identify gaps. An integrative review combines findings from diverse methodologies — experimental and non-experimental, quantitative and qualitative. An umbrella review synthesises existing systematic reviews. A rapid review streamlines systematic methods to deliver evidence under time pressure. A meta-analysis statistically pools quantitative results across studies, and is frequently a component of a systematic review rather than a separate design.
How to choose
Start from the question and the decision it informs. If you need a defensible answer to a focused effectiveness or accuracy question, choose a systematic review, and add a meta-analysis if the included studies are similar enough to pool. If the field is broad, emerging or ill-defined, a scoping review will map what exists and where the gaps are. If many systematic reviews already exist on overlapping questions, an umbrella review synthesises them. If you must report quickly, a rapid review trades some comprehensiveness for speed, and should say so transparently. For a student survey or a journal introduction, a narrative review is usually appropriate. Always weigh the time, expertise and number of reviewers available, since the more rigorous designs are resource-intensive and benefit from at least two independent screeners.
Reporting and rigour vary by type
The review types differ not only in aim but in how their conduct is reported. Systematic reviews are reported against the PRISMA 2020 statement, with a flow diagram accounting for every record screened, included and excluded; scoping reviews use a PRISMA extension designed for them. Narrative reviews carry no equivalent reporting standard, which is part of why their conclusions are weighted more cautiously. The general rule is that the more a review type claims to be comprehensive and reproducible, the more its method must be documented — search terms, eligibility criteria, appraisal and synthesis all laid out so the work can be checked or repeated. Matching the reporting effort to the review’s claims is what keeps the synthesis credible.
Key facts
At a glance
- Narrative: broad, flexible survey; no formal protocol
- Systematic: focused question, exhaustive reproducible protocol, PRISMA-reported
- Scoping: maps the breadth and nature of evidence; identifies gaps
- Integrative: combines diverse methodologies, quantitative and qualitative
- Umbrella: a review of existing systematic reviews
- Rapid: streamlined systematic methods under time constraints
Common questions
FAQ
What is the difference between a narrative and a systematic review?+
A narrative review surveys a topic selectively and flexibly, guided by the author’s judgement, with no pre-specified protocol — useful for breadth and context but open to selection bias. A systematic review answers a focused question using an exhaustive, transparent and reproducible method, usually reported against PRISMA 2020. The systematic approach minimises bias and can be repeated; the narrative approach offers flexibility and synthesis of a wide field.
Is a meta-analysis the same as a systematic review?+
No. A systematic review is the structured process of finding, appraising and synthesising studies that answer a focused question. A meta-analysis is a statistical method that pools quantitative results across those studies to produce a combined estimate. A systematic review may include a meta-analysis when the studies are similar enough to combine, but many systematic reviews synthesise narratively without one.
When should I use a scoping review instead of a systematic review?+
Use a scoping review when the aim is to map the breadth, range and nature of evidence on a broad or emerging topic, clarify concepts, or identify gaps — rather than to answer a single focused question. Scoping reviews do not usually appraise study quality formally. Choose a systematic review when you need a defensible answer to a specific, well-defined question.
