8. 9 Grading of recommendations and levels of evidence
Different types of trials are given a different weight when making recommendations in treatment guidelines.
UK Treatment guidelines use the system below in Table 1 to rate the different importance of different types of evidence.
For example, a recommendations rated AI should be followed as standard-of-care and can be supported by substantial clinical research.
Table: Grading of recommendations and levels of evidence
|Recommendation||Quality of evidence for recommendations|
|A: Required, should always be followed||(I) At least one randomised trial with clinical endpoints|
|B: Recommended, should usually be followed||(II) At least one randomised trial with surrogate markers|
|C: Optional||(III) Observational cohort data
(IV) Expert opinion based on other evidence
Last updated: 21 July 2009.