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Level of Evidence: Home

Assistance for determining level of evidence

Rating System

Hierarchy of Evidence for Intervention/Treatment Questions (in descending order)

Level I Evidence from a systematic review of meta-analysis of all relevant RCTs
Level II Evidence obtained from well-designed RCTs
Level III Evidence obtained from well-designed controlled trials without randomization
Level IV Evidence from well-designed case-control and cohort studies
Level V Evidence from systematic reviews of descriptive and qualitative studies
Level VI Evidence from single descriptive or qualitative studies
Level VII Evidence from the opinion of authorities and/or reports of expert communities

Table taken from Evidence-Based Practice in Nursing and Healthcare:  A Guide to Best Practice, 2011, page 12.  Print volume, 4th floor, Call #  WY 100.7 M527e 211