Table 3Definitions of the grades of overall strength of evidence

GradeDefinition
HighHigh confidence that the evidence reflects the true effect. Further research is very unlikely to change our confidence in the estimate of effect.
ModerateModerate confidence that the evidence reflects the true effect. Further research may change our confidence in the estimate of the effect and may change the estimate.
LowLow confidence that the evidence reflects the true effect. Further research is likely to change our confidence in the estimate of the effect and is likely to change the estimate.
InsufficientEvidence either is unavailable or does not permit estimation of an effect.

Source: Owens et al.85

From: Methods

Cover of Closing the Quality Gap: Revisiting the State of the Science (Vol. 4: Medication Adherence Interventions: Comparative Effectiveness)
Closing the Quality Gap: Revisiting the State of the Science (Vol. 4: Medication Adherence Interventions: Comparative Effectiveness).
Evidence Reports/Technology Assessments, No. 208.4.
Viswanathan M, Golin CE, Jones CD, et al.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.