03 October 2023

Quality of scientific evidence

The evidence pyramid visually shows the evidential strength of different types of research. All levels of the pyramid are “valid” evidence, but those at the higher levels are considered the most credible.

At the top of the pyramid is evidence including systematic reviews, meta-analyses, and critical appraisals. These studies evaluate and synthesize the literature. The top of the pyramid represents the strongest evidence.

Moving down the pyramid, randomised controlled trials, cohort studies and case reports can be found. It is important to find the highest level of evidence available, but that evidence at the top of the pyramid might not always exist exist for a particular research question.