Table 2

Thresholds for weighting risk factors

DescriptionThresholds and criteria for decision
Risk weighting (OR)Greatly increased riskMajority of ORs >2.5
Moderately increased riskMajority of ORs 1.5–2.5
Slightly increased riskMajority of ORs 1.1–1.5
No effectMajority of ORs <1.1
ConfidenceHighly confidentNumber, design and quality of studies, consistency of results, biological plausibility of factors
Moderately confident
Slightly confident
InconclusiveUnable to decide on riskInconsistent or insufficient evidence