Review type | Aims | Research question/ scope | Process | Literature searches | Inclusion criteria | Quality of evidence | Bias | Reviewers |
---|---|---|---|---|---|---|---|---|
Systematic | To inform clinical practice. | Narrow and well-defined. | Explicit, predefined, sequential process rigorously followed. | As exhaustive as possible; using pre-defined search strategy. | Predefined, (PICOS criteria) | Quality of evidence assessed and reported. | Systematic, explicit methods to minimize bias. | Requires at least two reviewers for study selection, data extraction and quality appraisal. |
Rapid | To inform service provision; caution when informing clinical practice. | Narrow and well-defined. | ‘Trimmed down’ systematic review process; shortcuts to minimise resources used. | Reduced list of sources searched; using search tools that facilitate finding literature. | Predefined, (PICOS criteria). | Quality of evidence assessed and reported. | Shortcuts may introduce bias. | Does not require two reviewers for study selection, data extraction and quality appraisal. |
Scoping | To map evidence, identify knowledge gaps, inform policy and practice. | Broader, initially parameters may not be clearly defined (e.g. type of intervention). | Iterative process, no formal requirement to include all steps. | Focus on comprehensiveness and breadth when defining search terms and sources. Can be altered at later stages. | Often developed post-hoc as reviewers become more familiar with available evidence. | No requirement to assess the quality of evidence. | Omitting/ altering steps may introduce bias. | Required number of reviewers not specified. |