Evidence synthesis and different types of reviews
Evidence syntheses combine data from multiple sources, most commonly from existing research studies, to provide an overall summary of current knowledge.
Evidence syntheses vs primary study
There is a difference between syntheses and primary studies. Syntheses sum up primary studies. But there are also synopses of syntheses.
Study designs
| Studytype | Scope | Quality |
|---|---|---|
| Direct observation | Direct measurement | highest |
| Meta-analysis | Synopses of syntheses | high |
| Systematic review | Syntheses | high |
| Evidence syntheses | Syntheses | high |
| RCT | Experimental | medium |
| Laboratory | Experimental | medium |
| Cohort | Observational | medium |
| Case control | Observational | medium |
| Cross sectional | Observational | medium |
| Case series | Descriptive | medium |
| Qualitative studies | Primary study | medium |
| Systematic expert opinion | Primary study | medium |
| Unystematic expert opinion | Primary study | medium |
A more detailled listing of evidence synthesis
- Rapid review: Rapidly summarize and synthesize existing evidence often for time-sensitive decision-making
- Literature review: Provide a broad overview of existing literature on a topic.
- Scoping review: Map and asses the extent of existing research on a broad topic often without specific research questions to identify key concepts, sources and gaps
- Systematic review: Answer a specific research question by systematically collecting, evaluating and synthesizing existing research studies
- Systematic review with meta-analysis: A meta-analysis is a quantitative, formal and epidemiological study design used to systematically assess the results of previous research to derive conclusions.
- Umbrella review: Synthesize findings from multiple systematic reviews and meta-analyses on a specific topic
- Living review: A review article that is updated at intervals to reflect the latest research