6S Evidence pyramid

The following is an overview of the 6S pyramid levels of evidence in descending order.

Systems:

Information from the lower levels of the hierarchy is integrated with individual patient records for clinical decision-making.

Summaries:

Clinical guidelines or textbooks that integrate evidence-based information about specific clinical problems.

Synopses of syntheses:

Summary of information found in systematic reviews. These may provide sufficient information to support clinical action.

Syntheses:

eta-analysis and systematic reviews are syntheses and provide a comprehensive summary of all the evidence surrounding a specific research question.

Synopsis of studies:

Summary of evidence from high-quality studies.

Studies:

Findings of a unique research study conducted to answer a specific clinical question.

Reference: Adapted from McMaster University Health Sciences Library, Resources for Evidence-based practice: The 6S pyramid and DiCenso A et al. Accessing pre-appraised evidence: fine-tuning the 5S model into a 6S model. Evidence-Based Nursing 2009;12:99-101