- Meta-analysis I
- Systematic reviews of RCTs
- Current practice guidelines
II- Randomized controlled trials
- Controlled trials without III
randomization (quasi-expermental) - Cohort studies (epidemiologic) IV
- Case-controlled studies
(epidemiologic)
V- Systematic review of descriptive
studies - Systematic review of qualitative
studies (meta-synthesis) - Correlational studies
VI- Single descriptive study
- Single qualitative study
- Case series studies (epidemiologic)
- Case reports
- Concept analysis
- Opinion of authorities• Reports of expert committees VII
- Manufacturer's recommendations
- Tr aditional literature reviews
HIGHESTLOWESTFIGURE 15-1 Evidence Hierarchy
15.2 Appraising the Evidence 409