Treatment training manual

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

Ref: www.bhiva.org

Last updated: 21 July 2009.