Evidence Based Practice Toolkit for Nursing

Created by OHSU Clinical Inquiry Council

Johns Hopkins Nursing EBP: Levels of Evidence

Level I
Experimental study, randomized controlled trial (RCT)
Systematice review of RCTs, with or without meta-analysis

Level II
Quasi-experimental Study
Systematic review of a combination of RCTs and quasi-experimental, or quasi-experimental studies only, with or without meta-analysis.

Level III
Non-experimental study
Systematic review of a combination of RCTs, quasi-experimental and non-experimental, or non-experimental studies only, with or without meta-analysis.
Qualitative study or systematice review, with or without meta-analysis

Level IV
Opinion of respected authorities and/or nationally recognized expert committees/consensus panels based on scientific evidence.
    Includes:
         - Clinical practice guidelines
         - Consensus panels

Level V
Based on experiential and non-research evidence.
    Includes:
      - Literature reviews
      - Quality improvement, program or financial evaluation
      - Case reports
      - Opinion of nationally recognized expert(s) based on experiential evidence

From Johns Hopkins nursing evidence-based practice : Models and Guidelines
Dearholt, S., Dang, Deborah, & Sigma Theta Tau International. (2012). Johns Hopkins Nursing Evidence-based Practice : Models and Guidelines.

Study Design

Different types of clinical questions are best answered by different types of research studies. 

You might not always find the highest level of evidence (i.e., RCT, systematic review/meta-analysis) to answer your question. When this happens, work your way down to the next highest level of evidence.

This table suggests study designs best suited to answer different types of clinical question.

Clinical Question

Suggested Research Design(s)

All Clinical Questions

Systematic review, meta-analysis

Therapy

Randomized controlled trial (RCT), meta-analysis
Also: cohort study, case-control study, case series

Etiology

Randomized controlled trial (RCT), meta-analysis, cohort study
Also: case-control study, case series

Diagnosis

Randomized controlled trial (RCT)
Also: cohort study

Prevention

Randomized controlled trial (RCT), meta-analysis
Also: prospective study, cohort study, case-control study, case series

Prognosis

Cohort study

Also: case-control study, case series

Meaning

Qualitative study

Quality Improvement

Randomized controlled trial (RCT)
Also: qualitative study

Cost

Economic evaluation

Evidence Appraisal

The Johns Hopkins Nursing EBP Evidence Level and Quality Guide is provided via the link below. 

There are lots of other evidence appraisal resources and tools available in the eBook, Johns Hopkins nursing evidence-based practice : Models and Guidelines


(From off-campus log in with your OHSU network username and password)

Dearholt, S., Dang, Deborah, & Sigma Theta Tau International. (2012). Johns Hopkins Nursing Evidence-based Practice : Models and Guidelines.

EBP Glossaries

Consult these resources to understand the language of evidence-based practice and terms used in clinical research.