Grading of Recommendations Assessment, Development, and Evaluations (GRADE) notes: extremely serious, GRADE's terminology for rating down by three levels

Objectives The Grading of Recommendations Assessment, Development, and Evaluations (GRADE) system for assessing certainty in a body of evidence currently uses two levels, serious and very serious, for downgrading on a single domain. In the context of newer risk of bias instruments, such as Risk of Bias in Non-Randomized Studies I (ROBINS-I), evidence generated by nonrandomized studies may justify rating down by more than two levels on a single...