Table 2.

New methodological tools and approaches for systematic reviews of prevalence studies.

	Methodological tool/approach	Information about the tool/approach	Reference
1	Protocols for the prevalence of exposure to occupational risk factors	Designed to transparently and consistently report planned methods that are standardized across the series of systematic reviews. Pre-publication of a peer-reviewed protocol discourages ad hoc decision-making that can bias a review and improves scientific quality by resolving methodological issues prior to conduct of a lengthy, resource-intensive evidence synthesis.	Descatha et al., 2018, Godderis et al., 2018, Hulshof et al., 2019, Li et al., 2018, Mandrioli et al., 2018, Paulo et al., 2019, Rugulies et al., 2019, Teixeira et al., 2019, Tenkate et al., 2019
2	Assessing risk of bias in studies estimating the prevalence of exposure to occupational risk factors (RoB-SPEO)	Designed to aid assessors in judging risk of bias of studies included in a systematic review of prevalence studies. Assessment follows standard practices in healthcare and environmental health systematic review (Higgins and Green, 2011, Rooney et al., 2014, Whaley et al., 2020; Woodruff and Sutton, 2011), facilitating qualitative judgement of the internal validity of studies across eight risk of bias domains.	Pega et al. (2020b)
3	Assessing the quality of evidence in studies estimating prevalence of exposure to occupational risk factors (QoE-SPEO)	Designed to aid assessment of the quality of a body of evidence supporting the findings of a systematic review of prevalence studies. The approach was developed to be consistent with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology for assessing certainty of evidence (Guyatt et al 2008; Morgan et al. 2016).	Pega et al. (Under review)