According to this system, there are two components to any treatment recommendation:

1. Designation of the strength of the recommendation (strong:1 or weak:2) depending on the risk and burden of a particular diagnostic test or a therapeutic procedure to the patient vs the expected benefit.
   • Strong recommendations (Grade 1) are those in which the benefits of an intervention outweighed its risks, or, alternatively, risks outweighed benefits.
   • Weak recommendations (Grade 2) are those in which the benefits and risks were less certain, either because of low quality evidence or because high quality evidence suggests benefits and risks are closely balanced.
2. An evaluation of the level of evidence (high:A, moderate:B, or low:C) based on the confidence that the estimate of effect is correct.
   • High-quality (A) evidence when additional research is considered very unlikely to change confidence in the estimate of effect.
   • Moderate-quality (B) evidence when further research is likely to have an important impact in the estimate of effect.
   • Low-quality (C) evidence when further research is very likely to change the estimate of the effect.