Oxford Centre For Evidence Based Medicine Levels Of Evidence 2011
As a healthcare professional, it is essential to have access to reliable and up-to-date information to make informed decisions about patient care. The Oxford Centre for Evidence-Based Medicine (OCEBM) provides a framework for evaluating the strength of evidence used in clinical practice. In 2011, the OCEBM updated their levels of evidence, which we will explore in this article.
What is Evidence-Based Medicine?
Evidence-Based Medicine (EBM) is an approach to clinical practice that involves using the best available evidence to inform decisions about patient care. This approach involves critically evaluating the quality and relevance of the evidence and considering the patient's values and preferences when making decisions.
What are the Oxford Centre for Evidence-Based Medicine Levels of Evidence?
The OCEBM Levels of Evidence provide a hierarchy of study designs based on the strength of evidence they provide. The levels range from Level 1 (highest) to Level 5 (lowest) and are based on the study design, quality, and relevance of the evidence.
What are the Changes in the 2011 Update?
The 2011 update to the OCEBM Levels of Evidence included some significant changes. One of the main changes was the introduction of two new levels: Level 1A and Level 1B. These levels were added to provide a more precise hierarchy for evidence from systematic reviews and meta-analyses.
Another change was the reclassification of some study designs. For example, randomized controlled trials (RCTs) with narrow confidence intervals were promoted to Level 2A, while RCTs with wide confidence intervals were demoted to Level 2B.
What are the Levels of Evidence?
Here is a breakdown of the OCEBM Levels of Evidence:
- Level 1A: Systematic reviews (with homogeneity) of randomized controlled trials
- Level 1B: Individual randomized controlled trials (with narrow confidence intervals)
- Level 2A: Systematic reviews (with homogeneity) of cohort studies
- Level 2B: Individual cohort studies or low-quality randomized controlled trials (with wide confidence intervals)
- Level 3A: Systematic reviews (with homogeneity) of case-control studies
- Level 3B: Individual case-control studies
- Level 4: Case series (and poor-quality cohort and case-control studies)
- Level 5: Expert opinion without explicit critical appraisal, or based on physiology, bench research, or first principles
How are the Levels of Evidence Used in Clinical Practice?
The OCEBM Levels of Evidence are used to evaluate the strength of evidence supporting clinical decisions. For example, a Level 1A study (systematic review of randomized controlled trials) provides stronger evidence than a Level 4 study (case series).
Healthcare professionals use the levels of evidence to inform clinical practice guidelines and recommendations. For example, a guideline based on Level 1A evidence is likely to be more strongly recommended than a guideline based on Level 3B evidence.
Conclusion
The Oxford Centre for Evidence-Based Medicine Levels of Evidence provide a framework for evaluating the strength of evidence used in clinical practice. The 2011 update included some significant changes, including the introduction of two new levels and the reclassification of some study designs. Healthcare professionals use the levels of evidence to inform clinical practice guidelines and recommendations, with stronger evidence at higher levels of the hierarchy.