Table 4.

Classification of quality of evidence base for screening for gestational diabetes mellitus in indigenous women

GRADE symbol	Level of confidence in quality of evidence	Definition	Criteria
⊕ ⊕ ⊕ ⊕	High	We are confident the true effect lies close to the estimate of the effect.	One or more studies were appraised at low risk of bias.
⊕ ⊕ ⊕	Moderate	We are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.	No studies were appraised at low risk of bias, although one or more studies were appraised at moderate risk of bias.
⊕ ⊕	Low	Our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.	No studies were appraised as low or moderate risk of bias. One or more studies were appraised at high risk of bias.
⊕	Very low	We have very little confidence in the effect estimate.	The publications were not in a format that allowed appraisal of the effect estimate (e.g. opinion piece).