NHS 8050 Discussion Levels of Evidence
NHS 8050 Discussion Levels of Evidence
Think about your own project topic for this course. In your initial post, discuss the three different levels of evidence you could apply to your own paper in this course.
What are the levels of evidence used in the peer-reviewed articles that you found?
Are there white papers or opinion papers on your topic?
Is there an industry expert you could consult?
What did you find that is not evidence based, but could be appropriate?
Provide your findings for all three levels of evidence.
Post according to the Faculty Expectations Response Guidelines. Be sure to include at least one APA-formatted citation (in-text plus full reference). The citation should be from materials you have read during this unit. It may be from course textbooks, assigned readings, or an outside source.
Levels of evidence (sometimes called hierarchy of evidence) are assigned to studies based on the methodological quality of their design, validity, and applicability to patient care. These decisions gives the “grade (or strength) of recommendation.”
| Level of evidence (LOE) | Description |
| Level I | Evidence from a systematic review or meta-analysis of all relevant RCTs (randomized controlled trial) or evidence-based clinical practice guidelines based on systematic reviews of RCTs or three or more RCTs of good quality that have similar results. |
| Level II | Evidence obtained from at least one well-designed RCT (e.g. large multi-site RCT). |
| Level III | Evidence obtained from well-designed controlled trials without randomization (i.e. quasi-experimental). |
| Level IV | Evidence from well-designed case-control or cohort studies. |
| Level V | Evidence from systematic reviews of descriptive and qualitative studies (meta-synthesis). |
| Level VI | Evidence from a single descriptive or qualitative study. |
| Level VII | Evidence from the opinion of authorities and/or reports of expert committees. |
This level of effectiveness rating scheme is based on the following: Ackley, B. J., Swan, B. A., Ladwig, G., & Tucker, S. (2008). Evidence-based nursing care guidelines: Medical-surgical interventions. (p. 7). St. Louis, MO: Mosby Elsevier.
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., systematic review or 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 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 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 Pyramid (Levels of Evidence)
“Evidence Pyramid” is a product of Tufts University and is licensed under BY-NC-SA license 4.0