The health and medical sectors are the origin of some of the best established frameworks for assessing the quality of evidence. Below we outline some of the methodologies most commonly used.
Grading of Recommendations Assessment, Development, and Evaluation (GRADE) offers a transparent and structured process for developing and presenting summaries of evidence, including its quality, for systematic reviews and recommendations in health care.
GRADE specifies an approach to:
- framing questions
- choosing outcomes of interest and rating their importance
- evaluating the evidence
- incorporating evidence with considerations of values and preferences of patients and society to arrive at recommendations.
A number of resources, including the GRADE Working Group, are listed below to help you learn to apply this approach to assessing the quality of evidence.
GRADE guidelines: 3. Rating the quality of evidence
This article introduces the approach of Grading of Recommendations Assessment, Development and Evaluation (GRADE) to rating quality of evidence in health research.
Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group (GRADE)
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group began in the year 2000 as an informal collaboration of people with an interest in addressing the shortcomings of present grading systems in health care.
PRISMA - or Preferred Reporting Items for Systematic Reviews and Meta-Analyses - is an evidence-based minimum set of items for reporting in systematic reviews and meta-analyses. PRISMA can also be used as a basis for reporting systematic reviews of other types of research, particularly evaluations of interventions. It may also be useful for critical appraisal of published systematic reviews, although it is not a quality assessment instrument in itself. It's worth noting that some questions have been raised about the applicability of the systematic review approach to international development and/or about how that approach has been applied.
The PRISMA Statement consists of a 27-item checklist and a four-phase flow diagram. The checklist includes items deemed essential for transparent reporting of a systematic review.
Below are some key resources which go into more detail about the meaning and rationale of the checklist items, and explain how to apply the PRISMA Statement.
The PRISMA Statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration
In this Explanation and Elaboration document, the authors explain the meaning and rationale for each checklist item. For each item, the authors include an example of good reporting and, where possible, references to relevant empirical studies and methodological literature.
PRISMA: Transparent Reporting of Systematic Reviews and Meta-Analyses (PRISMA)
The website provides access to the PRISMA checklist and the flow diagram, and provides the current definitive version of the PRISMA Statement.
UK National Institute of Clinical Excellence (NICE)
The National Institute for Health and Clinical Excellence (NICE) is the independent organisation responsible for providing national guidance on the promotion of good health and the prevention and treatment of ill health.
One important element in the development of their guidance is a rigerous assessment of the quality of the evidence base. This involves using an appropriate quality appraisal checklist, which are included in the NICE resources below.
Methods for the development of NICE public health guidance, third edition
The structure of this manual follows the methods for development of NICE public health guidance from inception to publication.
National Institute for Health and Clinical Excellence, UK (NICE)
NICE is the independent organisation responsible for providing national guidance on the promotion of good health and the prevention and treatment of ill health.