title: GRADE guidelines: 9. Rating up the quality of evidence.
abstract: The most common reason for rating up the quality of evidence is a large effect. GRADE suggests considering rating up quality of evidence one level when methodologically rigorous observational studies show at least a two-fold reduction or increase in risk, and rating up two levels for at least a five-fold reduction or increase in risk. Systematic review authors and guideline developers may also consider rating up quality of evidence when a dose-response gradient is present, and when all plausible confounders or biases would decrease an apparent treatment effect, or would create a spurious effect when results suggest no effect. Other considerations include the rapidity of the response, the underlying trajectory of the condition, and indirect evidence.
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, McMaster University, 1200 Main Street, West Hamilton, Ontario L8N 3Z5, Canada. guyatt@mcmaster.ca
authors.forename: Gordon H
authors.initials: GH
authors.lastname: Guyatt
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Oxman
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Sultan
authors.forename: Paul
authors.initials: P
authors.lastname: Glasziou
authors.forename: Elie A
authors.initials: EA
authors.lastname: Akl
authors.forename: Pablo
authors.initials: P
authors.lastname: Alonso-Coello
authors.forename: David
authors.initials: D
authors.lastname: Atkins
authors.forename: Regina
authors.initials: R
authors.lastname: Kunz
authors.forename: Jan
authors.initials: J
authors.lastname: Brozek
authors.forename: Victor
authors.initials: V
authors.lastname: Montori
authors.forename: Roman
authors.initials: R
authors.lastname: Jaeschke
authors.forename: David
authors.initials: D
authors.lastname: Rind
authors.forename: Philipp
authors.initials: P
authors.lastname: Dahm
authors.forename: Joerg
authors.initials: J
authors.lastname: Meerpohl
authors.forename: Gunn
authors.initials: G
authors.lastname: Vist
authors.forename: Elise
authors.initials: E
authors.lastname: Berliner
authors.forename: Susan
authors.initials: S
authors.lastname: Norris
authors.forename: Yngve
authors.initials: Y
authors.lastname: Falck-Ytter
authors.forename: M Hassan
authors.initials: MH
authors.lastname: Murad
authors.forename: Holger J
authors.initials: HJ
authors.lastname: Schünemann
mesh_terms: D019317:Evidence-Based Medicine / Q000592:standards* / Q000706:statistics & numerical data; D006801:Humans; D015588:Observer Variation; D017410:Practice Guidelines as Topic / Q000592:standards; D012306:Risk