Levels of Evidence
Describe the “levels of evidence” and provide an example of the type of practice change that could result from each. 2 references, please.
Levels of Evidence
The levels of evidence also referred to as a hierarchy of evidence, are assigned to studies based on the quality of the methodology, research design, validity of research results, and applicability of a research study to patient care (Burns et al., 2016). This criteria, therefore, provides the grade of recommendation. They are different grades assigned at the level of evidence beginning with level I to level VII. Level I evidence is the highest quality of evidence and includes evidence from meta-analysis or systematic reviews from relevant randomized controlled trials. A practice change related to therapy could therefore result from level I evidence (Ingham-Broomfield, 2018). On the other hand, level II evidence entails evidence that will be obtained from well-designed randomized controlled trials, for instance, a large multisite RCT. An etiological-based practice change can therefore result from level II evidence (Burns et al., 2016). Level III evidence will include evidence that is obtained from well-designed controlled trials that are not randomized such as quasi-experimental studies. A practice change related to the comparison of the effectiveness of different interventions could therefore result from level III evidence (Ingham-Broomfield, 2018). Level IV evidence includes evidence from cohort studies and case-control studies. A practice change related to the diagnosis of diseases can result from level IV evidence. Level V evidence includes evidence from systematic reviews of qualitative and descriptive studies. A practice change explaining the meaning of certain interventions can therefore result from level V evidence (Burns et al., 2016). Level VI evidence and entails evidence from a single qualitative or descriptive study. A practice change related to quality improvement can result from level VI evidence. Finally, level VII evidence includes evidence from expert reports or the opinions of authorities. Clinical guidelines can be extracted from level VII evidence (Ingham-Broomfield, 2018).
- Burns, P. B., Rohrich, R. J., & Chung, K. C. (2016). The levels of evidence and their role in evidence-based medicine. Plastic and reconstructive surgery, 128(1), 305–310. https://doi.org/10.1097/PRS.0b013e318219c171.
- Ingham-Broomfield, R., (2018). A nurses’ guide to the hierarchy of research designs and evidence. Australian Journal of Advanced Nursing Vol. 33 Iss. 3. https://www.ajan.com.au/archive/Vol33/Issue3/5Broomfield.pdf.v