Evidence Synthesis Librarians
Kudos
Resources
- Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health information and libraries journal, 26(2), 91–108. https://doi.org/10.1111/j.1471-1842.2009.00848.x
- Sadruddiin, S.S., Vaska, M., Ahmed, S. and Turin, T.C. (2017). Review Typology: The Basic Types of Reviews for Synthesizing Evidence for the Purpose of Knowledge Translation. Journal of the College of Physicians and Surgeons Pakistan, 27(10), 635-641.
- Sutton, A., Clowes, M., Preston, L., & Booth, A. (2019). Meeting the review family: Exploring review types and associated information retrieval requirements. Health information and libraries journal, 36(3), 202–222. https://doi.org/10.1111/hir.12276
Types of Reviews
About Evidence Synthesis Types
| Review Type | Description | Search Method | Appraisal of Quality | Synthesis | Analysis |
|---|---|---|---|---|---|
| Critical review |
Critically evaluates research in a specific area - its effectiveness and quality Typically results in a hypothesis or model rather than an answer to a question |
Extensive search aims to identify the most significant and impactful sources |
No formal quality appraisal required Evaluation is based on the contribution of each source |
Typically narrative; may be conceptual or chronological |
Incorporates significant analysis using criteria such as strengths, weaknesses, or validity of cited sources Identify level of significance, contribution of sources to an overall concept, or derive new theory |
| Integrative Review | Evaluates and integrates both empirical and theoretical studies to address a clinical (or other) problem | Comprehensive and exhaustive search required | Formal quality appraisal required | Tables, narrative | Identify patterns and themes among sources and provide recommendations for practice and/or future research |
| Literature review |
A generic term Provides a broad overview of a research area or describes literature on a topic to summarize what has been accomplished or identify gaps. Not comprehensive in nature |
Comprehensive search not required No formal criteria for selecting relevant resources |
No formal quality appraisal required |
Typically narrative |
Analysis may be chronological, conceptual, thematic, etc. |
| Mapping review / Evidence or Gap Map |
Map out and classify quality and quantity of existing studies on a topic Identifies gaps and provides directions for future research |
Comprehensiveness depends on time/scope constraints | No formal quality appraisal required |
Graphs, tables, and data representations, e.g. interactive data visualizations / maps |
Define quantity and quality of available literature based on relevant facets |
| Meta-analysis | Statistically combines the results of quantitative studies on a topic to create a larger and more complete picture of the results | Comprehensive and exhaustive search required |
Formal quality appraisal is required Use appraisal to determine inclusion/exclusion of studies, overall quality of studies included, and sensitivity analyses |
Statistics, graphs, tables, and narrative |
Requires homogeneity of included studies for analyses to take place Statistical analysis of effect size |
| Mixed methods review |
Synthesize qualitative and quantitative data to develop overarching conclusions Typically uses systematic review, comprehensive search methods |
Uses either a comprehensive systematic review search strategy to retrieve all studies, or multiple comprehensive search strategies to retrieve quantitative and also qualitative studies |
Formal quality appraisal is required Either use one appraisal tool (MMAT) or separate appraisal tools with comparable criteria to combine for final synthesis |
Graphs, tables and narrative Goal is synthesizing qualitative and quantitative information |
May characterize, compare and contrast, or identify gaps in different literature types (quantitative and/or qualitative) |
| Qualitative review |
Integrate and compare results from qualitative studies Aim is to identify frequently occurring themes or constructs within and/or across studies |
Comprehensiveness varies May use selective sampling-only |
Appraisal methods typically serve to mediate messages rather than for determining inclusion/exclusion of studies | Qualitative, narrative synthesis |
Thematic analysis May include conceptual models |
| Rapid review |
An expedited collection, assessment and synthesis of studies on a topic to inform policy or practice Uses abbreviated (and transparently reported) elements of systematic review methods adapted for a shorter timeline |
Comprehensive search not required |
Formal quality appraisal is required Use a time-limited formal appraisal method |
Tables, narrative | Define the quantity, quality, and direction of the literature |
| Scoping review |
Provide an initial exploratory analysis of nature, size, and scope of research on a broad (or multiple related) topic/s not yet examined Identify what is known on a topic and directions for future research |
Comprehensive and exhaustive search Typically includes grey literature |
Formal quality appraisal not required | Tables, narrative |
Describe the quantity, quality, size, scope and types of available literature on a topic Often leads to future systematic reviews |
| State-of-the-art review |
Focuses on recently published literature to assess current issues Contrasts with retrospective or current approaches Highlights new ideas, gaps or points to future research |
Comprehensive and exhaustive search of current literature | Formal quality appraisal not required | Tables, narrative | Describes current state of knowledge on a topic and priorities for future research |
| Systematic review |
Identify and synthesize research on a focused topic Uses pre-established replicable methods for search, appraisal, and synthesis of literature |
Comprehensive and exhaustive |
Formal quality appraisal is required Use formal critical appraisal methods to determine the inclusion/exclusion of studies and quality of studies included |
Tables, narrative | Define what is known, unknown, or uncertain and provide recommendations for practice and/or future research |
| Systematic search and review | A comprehensive search, analysis, and synthesis of material from diverse sources. Typically seeks to answer a broad question and provide best evidence | Comprehensive and exhaustive | May include formal quality appraisal | Tables, narrative | Define what is known, provide recommendations for practice, discuss limitations |
| Systematized review |
Describes most cases in which graduate students conduct an evidence synthesis Uses abbreviated (and transparently reported) elements of systematic review methods adapted for a shorter timeline |
Elements of comprehensive and exhaustive search |
May include quality appraisal May use a time-limited formal appraisal method |
Narrative, tables |
Define what is known, unknown, or uncertain about a topic. Acknowledges procedural limitations. |
| Umbrella review |
A systematic review of systematic reviews. Compiles and synthesizes evidence from multiple systematic reviews on a broad topic in which there are multiple differing conclusions / summaries |
Comprehensive and exhaustive search is required Search looks for systematic reviews and other evidence synthesis, not primary studies |
Formal quality appraisal is required Appraisal method evaluates quality of studies within each review as well as the overall systematic review/evidence synthesis |
Graphs, tables, narrative | Define what is known, unknown, or uncertain and provide recommendations for practice and/or future research |