Table 7.

Example of weight of evidence classifications.

Method/framework	Reference	Number of Classes	Class title
Bayesian Inference	Schleier et al. (2015)	NA	NA
Epid-Tox	Adami et al. (2011)	4	Likely, Uncertain, Uncertain but plausible, Unlikely (Used to qualify the causal relationship between the environmental factor and the disease condition)
GRADE	Andrews et al. (2013b)	4	Strong Against, Weak Against, Weak For, Strong For
Hope and Clarkson	Hope and Clarkson (2014)	5	Weak, Not indicated, Not indicated, Not indicated, Strong
IARC	IARC (2006)	5	Group 1: The agent is carcinogenic to humans Group 2A: The agent is probably carcinogenic to humans Group 2B: The agent is possibly carcinogenic to humans Group 3: The agent is not classifiable as to its carcinogenicity to humans Group 4: The agent is probably not carcinogenic to humans
Modified Bradford Hill	Meek et al. (2014a); OECD (2014)	3	Weak, Moderate, Strong
Multi-criteria analysis	Linkov et al. (2011)	6	Do nothing, Institutional control, Clay capping, Mechanical dredging, Hydraulic dredging, Hot spot dredging
NRC	NRC (2014)	5	Carcinogenic to humans, Likely to be carcinogenic to humans, Suggestive evidence of carcinogenic potential, Inadequate information to assess carcinogenic potential, Not likely to be carcinogenic to humans
OHAT	OHAT (2015)	5	(1) Known to be a hazard to humans, (2) Presumed to be a hazard to humans, (3) Suspected to be a hazard to humans, (4) Not classifiable as a hazard to humans, or (5) Not identified as a hazard to humans
SR–Cochrane	Higgins and Green (2011)	4	Very low, Low, Moderate, Strong
SR-EFSA	EFSA (2010)	NA	NA
SCENIHR	SCENIHR (2012)	5	Weighting not possible, Uncertain, Weak, Moderate, Strong
WCRF/AICR	WCRF/AICR (2014)	5	Convincing/Probable/Limited - suggestive/Limited - no conclusion/Substantial effect on risk unlikely

Note: EFSA, European Food Safety Authority; GRADE, Grading of Recommendations Assessment, Development and Evaluation; NA, Not applicable because the corresponding step was not addressed by the approach; NRC, U.S. National Research Council; OHAT, Office of Health Assessment and Translation; SCENIHR, Scientific Committee on Emerging and Newly Identified Health Risks; SR, Systematic Review; WCRF/AICR, World Cancer Research Fund and American Institute for Cancer Research.