Table 2 Quality assessment of the evidence
| Â | Quality Assessment | ||||
|---|---|---|---|---|---|
Number of studies | Study design(s) | Limitations | Consistency | Generalizability | Overall quality of evidence (justification) |
Effect Of Water Quality Interventions at Source | |||||
Outcome: Diarrhea incidence or prevalence | |||||
5 | 2 cRCT, 3 QE | 3 very low, 1 low, 1 moderate quality study | I2 = 81% Studies favoured intervention, control, or showed no effect | Children 0–5 years; low and middle income countries (Afghanistan, Bangladesh, Pakistan, Panama, Uzbekistan) | Very low (considerable heterogeneity, non-significant pooled estimate) |
Point-Of-Use Water Treatment Interventions | |||||
Intervention: Water filters and water disinfection, Outcome: Diarrhea incidence or prevalence | |||||
32 | 15 RCT, 12 cRCT, 5 QE | 17 very low, 11 low, 4 moderate quality studies | I2 = 89% Studies either favoured intervention or showed no effect | Children 0–5 years; low and middle income countries (Afghanistan, Bangladesh, Bolivia, Brazil, Cambodia, Colombia, Democratic Republic of Congo, Dominican Republic, Ethiopia, Ghana, Guatemala, Haiti, India, Honduras, Kenya, Pakistan, Saudi Arabia [rural], South Africa, Uzbekistan, Zimbabwe) | Low (15 studies were low or moderate quality, large significant magnitude of effect, considerable heterogeneity warrants further research on the magnitude of the benefit) |
Intervention: Water filters, Outcome: Diarrhea incidence or prevalence | |||||
13 | 8 RCT, 4 cRCT, 1 QE | 8 very low, 5 low quality studies | I2 = 84% Studies generally favoured intervention | Children 0–5 years; low and middle income countries (Bolivia, Cambodia, Colombia, Democratic Republic of Congo, Dominican Republic, Ethiopia, Ghana, Honduras, Kenya, South Africa, Zimbabwe) | Very low (mostly very low quality studies) |
Intervention: Water disinfection, Outcome: Diarrhea incidence or prevalence | |||||
19 | 7 RCT, 8 cRCT, 4 QE | 9 very low, 6 low, 4 moderate quality studies | I2 = 87% Studies either favoured intervention or showed no effect | Children 0–5 years; low and middle income countries (Afghanistan, Bangladesh, Bolivia, Brazil, Cambodia, India, Ethiopia, Ghana, Guatemala, Haiti, Kenya, Pakistan, Saudi Arabia [rural], Uzbekistan) | Low (studies ranged from very low to moderate quality, large significant magnitude of effect, considerable heterogeneity warrants further research on the magnitude of the benefit) |
Hand Washing Education with Soap Interventions | |||||
Outcome: Diarrhea incidence or prevalence | |||||
6 | 4 cRCT, 2 QE | 5 very low, 1 low quality study | I2 = 81% Studies either favoured intervention or showed no effect | Children 0–5 years; low and middle income countries (Bangladesh, India, Myanmar, Nepal, Pakistan) | Very low (most studies very low quality, considerable heterogeneity) |