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. 2019 Jun;222(5):765–777. doi: 10.1016/j.ijheh.2019.05.004

Table 2.

Information on counterfactual, outcome association and potential for bias by health outcome.

health outcome WASH counterfactual exposure definition prevalence of WASH counterfactual exposure in 2016 RR for/association between WASH counterfactual exposure and outcome# (against lowest level of exposure, e.g., unimproved WASH) counterfactual definition used potential for bias
diarrhoea water: household water treatment using filtering or boiling 33.1% (WHO and UNICEF, undated) RR 0.52 (0.35, 0.77)* (Wolf et al., 2018a) plausible minimum risk predominately non-blinded intervention studies but bias-adjustment performed
sanitation: basic sanitation in a community >75% sanitation coverage 45.3% (Wolf et al., 2018c) RR 0.55 (0.34, 0.91) (Wolf et al., 2018a)
hygiene: handwashing with soap after potential faecal contact 26.2% (Wolf et al., 2018b) RR 0.86 (0.35, 2.07)* (Wolf et al., 2018a)
acute respiratory infections hygiene: handwashing with soap after potential faecal contact 26.2% (Wolf et al., 2018b) RR 0.84 (0.79, 0.89) (Rabie and Curtis, 2006) plausible minimum risk predominantly non-blinded intervention studies
protein-energy malnutrition same as for diarrhoea same as for diarrhoea combining the PAF for stunting attributable to diarrhoea (25% (8%, 38%)) (Checkley et al., 2008) with the PAF of WASH-attributable diarrhoeal disease (60% (54%, 65%)) same as for diarrhoea includes only WASH-attributable burden via diarrhoea, only stunting is considered as indicator for malnutrition
schistosomiasis basic drinking water and basic sanitation services basic drinking water: 87.2%; basic sanitation: 62.0% (WHO and UNICEF, undated) basic drinking water: RR 0.53 (0.47, 0.61) (Grimes et al., 2014); basic sanitation: RR 0.65 (0.54, 0.78) (Freeman et al., 2017) feasible minimum risk RR estimates from observational studies only
malaria safe water resource management 0% (Keiser et al., 2005) RR 0.21 (0.13–0.33) (Keiser et al., 2005) theoretical minimum risk disease burden estimates based on stronger assumptions
soil-transmitted helminth infections safely managed water and safely managed sanitation services, essential hygiene conditions and essential hygiene practices NA RR 0 theoretical minimum risk disease burden estimates based on stronger assumptions
trachoma safely managed water and safely managed sanitation services, essential hygiene conditions and essential hygiene practices NA RR 0 theoretical minimum risk disease burden estimates based on stronger assumptions

RR: relative risk, NA: not applicable, # separate RR for water, sanitation and hygiene are combined using equation (2), * adjusted for potential non-blinding bias.