A term used to describe a clinical practice based on studies published in the scientific literature. The publications must be peer reviewed by experts to ensure their quality. Quality depends on scientifically rigorous methods of data collection, analysis, and interpretation. No single study, regardless of the quality of its design, is sufficient by itself to serve as the basis for evidence. Findings must be replicated in several studies, and findings must be consistent. The strength or degree of evidence amassed for any intervention is referred to as the level of evidence.