In the era of Evidence-Based Medicine (EBM), scientific testimonials are the cornerstone upon which, theories are formulated, policies are made, and knowledge advances. In the evidence pyramid, high-quality randomized controlled trials (RCTs) have been accepted as the gold standard for primary data sources. Evidence from the base of the pyramid is considered low-rated. However, it is crucial to recognize and appreciate the importance of low-level evidence in the broader spectrum of scientific evidence. While these forms of evidence may lack the rigor and statistical power associated with RCTs, they offer unique contributions that enrich the research process in several ways. Low-level evidence is indispensable in biomedical research, particularly in the early stages of an outbreak and in contexts where high-level evidence is not yet available or feasible. While low-level evidence might give unique insights and cover specific knowledge gaps, it should be considered complementary to the higher-quality evidence.
Biomedical Research, Evidence-Based Medicine, Expert opinion, Research Design, Risk Factors