Level I
Experimental Study, randomized controlled trial (RCT)
Systematic 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 designs best suited to answer each type of clinical question.
|
Clinical Question |
Suggested Research Design(s) |
|
All Clinical Questions |
Systematic review, meta-analysis |
|
Therapy |
Randomized controlled trial (RCT), meta-analysis |
|
Etiology |
Randomized controlled trial (RCT), meta-analysis, cohort study |
|
Diagnosis |
Randomized controlled trial (RCT) |
|
Prevention |
Randomized controlled trial (RCT), meta-analysis |
|
Prognosis |
Cohort study Also: case-control study, case series |
|
Meaning |
Qualitative study |
|
Quality Improvement |
Randomized controlled trial (RCT) |
|
Cost |
Economic evaluation |