Evidence-based practice (EBP) is utilizing best research evidence and integrating it with the practitioner's expertise and patient values. EBP provides nurses with improved actions and activities to effectively deliver patient care. EBP journals include articles based on evidence and clinical expertise for the best available patient care and decision-making practices. EBP articles include a discussion of current research or a literature review related to the article topic.

To evaluate EBPs, levels of evidence are used.

It is important to evaluate or identify the level of evidence to determine if it is credible, valid, reliable, and appropriate for practice. For example, randomized controlled trials (RCT), designed to be unbiased and with less risk of errors, are at the highest level, whereas literature reviews, case reports or expert opinions are at the lowest level. When searching for evidence-based information, choose the highest level of evidence: randomized controlled trials (RCT) and systematic review of RTCs, with or without meta-analysis.

See opens new windowJohns Hopkins Nursing Evidence-Based Practice for five Evidence Levels and Quality Guide, or do a web search for "levels of evidence in nursing research" to view charts, tables, graphs and text on the topic.

Several criteria can be used to determine if evidence is reliable for evidence-based practice (EBP):

Source Credibility

• Peer-reviewed Articles - These articles are published in peer-reviewed journals and have undergone rigorous evaluation by experts in the field before publication. This process verifies the research validity and reliability.
• Reputable Organizations - Information from well-known organizations such as the WHO, CDC, American Medical Association (AMA), or other major is typically reliable. 

Study Design - Levels of Evidence

Level I (Highest level of evidence)

• Experimental study, randomized controlled trial (RCT)
  • Participants are randomly assigned to either the intervention or control group. Due to randomization, which minimizes bias and confounding or extraneous variables. RCTs are considered the gold standard in clinical research.
• Systematic Reviews of RCTs
  • These reviews synthesize data from multiple RCT studies, providing a high level of evidence by analyzing results across a range of settings and populations, thus reducing bias and increasing reliability. They combine data from various studies, often including randomized controlled trials (RCTs), which are themselves high-quality sources of evidence.
• Meta-Analyses
  • Systematic reviews that use statistical methods to combine the results of multiple studies. They are considered very high levels of evidence because they can provide more precise estimates of treatment effects.

Level II

• Quasi-experimental Studies
  • Similar to RCTs and attempt to infer causality between an intervention and outcome, but participants are assigned to a group based on certain criteria. Group assignment is not random. Where randomization is not possible, these are useful for evaluating interventions impacts in natural settings.
• Systematic Reviews of Quasi-experimental Studies
  • Reviews of a quasi-experimental studies only, or a combination of RCTs and quasi-experimental studies.
• Single RCTs

Level III

• Non-experimental Study
  • Studies that include observance of natural occurrences, such as observational studies, case-control studies, cross-sectional studies.
• Systematic Review of Mixed Studies
  • Systematic review that includes a mix of RCTs, quasi-experimental studies, and non-experimental studies, with or without meta-analysis.
• Cohort Studies, qualitative study or systematic review, with or without meta-analysis

Level IV

• Recommendations and Opinions
  • Recommendations from or opinions of esteemed authorities or nationally recognized expert committee or consensus panels based on scientific evidence. Includes clinical practice guidelines and consensus panel reports. 
• Clinical practice guidelines
• Consensus panels

Level V

• Experiential and Non-Research Evidence
  Includes: Literature reviews, quality improvements or programs, case reports, and opinions from nationally recognized experts grounded in experiential evidence.

What are Evidence-Based Care Sheets?

opens new windowCINAHL Evidence-Based Care Sheets (EBCS) are summaries on specific key topics, which are focused on nursing practice. Each evidence-based care sheet incorporates the latest evidence, statistics, research and references on a given topic.

To browse and search the list of Evidence-Based Care Sheets:

1. Go to opens new windowCINAHL.
2. Click Evidence-Based Care Sheets in the top toolbar.
3. Browse the alphabetical list of topics or key in a search term in the browsing text box.
4. To view, mark the checkbox in front of one or several topics, then click Search.

Examples:

• Schub, T., & Woten, M. (2018). opens new windowFall Prevention in Hospitalized Patients. CINAHL Nursing Guide.
• Walsh, K., & Schub, T. (2018). opens new windowOsteoporosis in Men. CINAHL Nursing Guide.
• DeVesty, G., & Avital, O. (2021). opens new windowMacular Degeneration, Age-Related: Quality of Life. CINAHL Nursing Guide.

Note: For citations, always check the print manual and follow your professor's requirement.