The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach

Judgments about evidence and recommendations in healthcare are complex. Healthcare evidence and subsequent recommendations leave decision makers with differing degrees of certainty in that evidence. Sources of evidence range from small laboratory studies or case reports to well-designed large randomized controlled trials that have minimized bias to a great extent. The GRADE began in the year 2000 as a collaboration of methodologists, guideline developers, biostatisticians, clinicians, public health scientists and other interested members. GRADE developed and implemented a common, transparent and sensible approach to grading the quality of evidence (also known as certainty in evidence or confidence in effect estimates) and strength of recommendations in healthcare[3][4] The GRADE approach separates recommendations following from an evaluation of the evidence as strong or weak. A recommendations to use, or not use an option (e.g. an intervention), should be based on the trade-offs between desirable consequences of following a recommendation on the one hand, and undesirable consequences on the other (Table 2). If desirable consequences outweigh undesirable consequences, decision makers will recommend an option and vice versa. The uncertainty associated with the trade-off between the desirable and undesirable consequences will determine the strength of recommendations.[5] The criteria that determine this balance of consequences are listed in Table 2. Furthermore, it provides decision-makers (e.g. clinicians, other health care providers, patients and policy makers) with a guide to using those recommendations in clinical practice, public health and policy. To achieve simplicity, the GRADE approach classifies the quality of evidence in one of four levels—high, moderate, low, and very low:

Table 1. Quality of evidence and definitions (modified from [6])

The GRADE working group has developed a software application that facilitates the use of the approach, allows the development of summary tables and contains the GRADE handbook. The software is free for non-profit organizations and is available online.[7] The GRADE approach to assess the certainty in evidence is widely applicable, including to questions about diagnosis,[8][9] prognosis,[10][11] network meta-analysis[12] and public health.[13]

Over 100 organizations (including the World Health Organization, the UK National Institute for Health and Care Excellence (NICE), the Canadian Task Force for Preventive Health Care, the Colombian Ministry of Health, among others) have endorsed and/or are using GRADE to evaluate the quality of evidence and strength of health care recommendations. (See examples of clinical practice guidelines using GRADE online).[14][15]

Table 2. Factors and criteria that determine the direction and strength of a recommendation

• Factors for which overlap is described are often not shown separately in a decision table.