Librarian
Levels of Evidence / Evidence Hierarchy
Levels of evidence (sometimes called hierarchy of evidence) are assigned to studies based on the research design, quality of the study, and applicability to patient care. Higher levels of evidence have less risk of bias.
Levels of Evidence (Melnyk & Fineout-Overholt 2023)
|
Level of Evidence |
Description |
| Level 1 |
Evidence from a systematic review or meta-analysis of all relevant RCTs (randomized controlled trials). |
|
Level 2 |
Evidence from at least one well-designed RCT (e.g. large multi-site RCT). |
|
Level 3 |
Evidence from a single well-designed controlled trials without randomization (aka quasi-experimental studies) OR a systematic review of a complete BOE (integrative review of higher and lower evidence) OR mixed methods intervention studies
|
|
Level 4 |
Evidence from well-designed case-control or cohort studies |
|
Level 5 |
Evidence from systematic reviews of descriptive and qualitative studies (meta-synthesis) |
|
Level 6 |
Evidence from a single descriptive or qualitative study, EBP, EBQI and QI projects |
|
Level 7 |
Evidence from the opinion of authorities and/or reports of expert committees, reports from committees of experts and narrative and literature reviews |
*Adapted from: Melnyk, & Fineout-Overholt, E. (2023). Evidence-based practice in nursing & healthcare: A guide to best practice (Fifth edition.). Wolters Kluwer.
Levels of Evidence / Evidence Hierarchy
Levels of Evidence (LoBiondo-Wood & Haber 2022)
Level |
Research Designs |
|---|---|
| 1 | Systematic Review or meta-analysis of RCTs (randomized control trials) |
| 2 | Randomized control trials |
| 3 | Quasi-experimental Studies |
| 4 | Non-experimental studies |
| 5 | Meta-synthesis |
| 6 | Qualitative studies |
| 7 | Expert opinions: reports from expert panels and organizations, not based on research |
Adapted from LoBiondo-Wood, G. & Haber, J. (2022). Nursing research: Methods and critical appraisal for evidence-based practice (10th ed.). Elsevier.
Evidence Pyramid (Levels of Evidence)
"Evidence Pyramid" is a product of Tufts University and is licensed under BY-NC-SA license 4.0
Tufts' "Evidence Pyramid" is based in part on the Oxford Centre for Evidence-Based Medicine: Levels of Evidence (2009)
Evidence-Based Nursing Care Guidelines by
This groundbreaking reference - created by an internationally respected team of clinical and research experts - provides quick access to concise summaries of the body of nursing research for 192 common medical-surgical interventions. Each nursing care guideline classifies specific nursing activities as Effective, Possibly Effective, or Possibly Harmful, providing a bridge between research and clinical practice. Ideal for both nursing students and practicing nurses, this evidence-based reference is your key to confidently evaluating the latest research findings and effectively applying best practices in the clinical setting. Synthesizing the current state of research evidence, each nursing care guideline classifies specific activities as Effective, Possibly Effective, Not Effective, or Possibly Harmful. Easy-to-recognize icons for each cited study help you differentiate between findings that are based on nursing research (NR), multidisciplinary research (MR), or expert opinion (EO), or those activities that represent established standards of practice (SP). Each nursing activity is rated by level of evidence, allowing you to gauge the validity of the research and weigh additional evidence you may encounter. Guidelines are identified by NIC intervention labels wherever appropriate, and NOC outcome measurements are incorporated throughout. An Evolve website provides additional evidence-based nursing resources.
Call Number: Main Collection - 2nd Floor ; RT51 .E95 2008ISBN: 9780323046244Publication Date: 2007-02-18
Definitions
- SAGE Research Methods: Foundations This link opens in a new windowProvides introductory overviews to major research methodologies, research ethics, and biographical sketches of researchers.
Encyclopedia of Nursing Research by Call Number: eBookISBN: 9780826133045Publication Date: 2017-07-01Comprehensive and concise, entries provide the most relevant and current research perspectives and demonstrate the depth and breadth of nursing research today. This one-stop reference presents key terms and concepts and clarifies their application to practice. The fourth edition has been substantially updated to contain the latest research for nurse scientists, educators, and students in all clinical specialties.
