GRADE system classification scheme

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was developed to determine the strength of recommendations as strong (1) or weak (2) and to guide assessment of quality of evidence from high (A) to very low (D).

Strength of Recommendations

The GRADE system classifies recommendations as strong (grade 1) or weak (grade 2). Factors influencing this determination are as follows:

What Should be Considered	Recommended Process
High or moderate evidence (Is there high or moderate quality evidence?)	The higher the quality of evidence, the more likely a strong recommendation.
Certainty about the balance of benefits vs. harms and burdens (Is there certainty?)	The larger the difference between the desirable and undesirable consequences and the certainty around that difference, the more likely a strong recommendation. The smaller the net benefit and the lower the certainty for that benefit, the more likely a weak recommendation.
Certainty in or similar values (Is there certainty or similarity?)	The more certainty or similarity in values and preferences, the more likely a strong recommendation.
Resource implications (Are resources worth expected benefits?)	The lower the cost of an intervention compared to the alternative and other costs related to the decision–ie, fewer resources consumed–the more likely a strong recommendation.