Critical appraisal is systematic evaluation of the research question, methods, and outcomes of a study. Utilizing methods of critical appraisal is important in determining both the quality of evidence presented and the relevance of the research to the public health needs of your community. Many tools that are designed for health care professionals outline the same key concepts and standards that are used in public health appraisal and can be used when compiling evidence for decisions about public health programs, policies, and practices.
Publication types are ranked in evidence pyramids based on the rigor of evidence provided by the research design. The higher the study design is on the pyramid, the higher the level of evidence. However, this also means there are fewer documents of this type.
High level evidence from the top of the pyramid is preferred, but not always available for all questions. Remember that the type of question you are asking will help determine which types of studies would be most appropriate.
Check out the links below for more information of the different levels of evidence and research study designs.