Systematic Reviews and Meta-Analysis are widely considered the gold-standard approach to summarizing and synthesizing evidence. The authors who developed the graphic below suggest that these may be viewed as tools for consuming evidence. Study design on its own is not enough to evaluate for evidence quality. Study methodology needs to be assessed for limitations and quality of evidence through critical appraisal. Evidence quality may then inform the use of a grading system such as the one developed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group which rates evidence quality when making guideline recommendations.
Murad MH, Asi N, Alsawas M, Alahdab F. New evidence pyramid. Evid Based Med. 2016;21(4):125-127. doi:10.1136/ebmed-2016-110401