Table 2.
Subgroup meta-analyses for the effect of WASH interventions alone on child growth outcomes stratified by characteristics of the included studies
| Potential effect modifier | HAZ | WAZ | WHZ | ||||||
| No. of studies |
I
2 (%), p value |
Pooled MD (95% CI) |
No. of studies | I2 (%), p value |
Pooled MD (95% CI) |
No. of studies | I2 (%), p value |
Pooled MD (95% CI) |
|
| Age* | |||||||||
| 0–2 years | 4 | 74 to 0.01 | 0.07 (0.01 to 0.13) | 3 | 85 to 0.003 | 0.00 (−0.15 to 0.16) | 0 | n/a | n/a |
| <5 years | 4 | 72 to 0.01 | 0.05 (−0.00 to 0.11) | 3 | 74 to 0.02 | −0.00 (−0.10 to 0.09) | 0 | n/a | n/a |
| Setting | |||||||||
| Pre-urban and rural | 1 | n/a | 0.11 (−0.19 to 0.41) | 1 | n/a | −0.01 (−0.23 to 0.21) | 1 | n/a | −0.11 (−0.30 to 0.08) |
| Urban slum | 1 | n/a | −0.13 (−0.54 to 0.28) | 1 | n/a | 1 | n/a | −0.11 (−0.53 to 0.31) | |
| Rural | 14 | 74, <0.001 | 0.02 (−0.04 to 0.09) | 13 | 38 to 0.08 | −0.02 (−0.06 to 0.01) | 9 | 0 to 0.62 | −0.02 (−0.06 to 0.02) |
| Length of intervention | |||||||||
| 6–12 months | 5 | 22 to 0.27 | −0.04 (−0.12 to 0.03) | 5 | 0 to 0.95 | −0.05 (−0.11 to −0.00) | 2 | 0 to 1.00 | −0.11 (−0.29 to 0.07) |
| 18–60 months | 11 | 76, <0.001 | 0.04 (0.01 to 0.08) | 10 | 48 to 0.04 | −0.01 (−0.06 to 0.04) | 9 | 0 to 0.62 | −0.02 (−0.06 to 0.02) |
| Geographical region | |||||||||
| Sub-Saharan Africa | 6 | 80, <0.001 | 0.06 (0.01 to 0.10) | 5 | 58 to 0.05 | −0.02 (−0.06 to 0.03) | 3 | 0 to 0.73 | −0.05 (−0.11 to 0.01) |
| Southern Asia | 7 | 73 to 0.001 | 0.01 (−0.13 to 0.15) | 7 | 24 to 0.24 | −0.04 (−0.10 to −0.01) | 5 | 0 to 0.93 | −0.02 (−0.09 to 0.05) |
| Southeast Asia | 1 | n/a | 0.01 (−0.09 to 0.11) | 1 | n/a | 0.03 (−0.06 to 0.12) | 1 | n/a | 0.06 (−0.04 to 0.16) |
| South America | 2 | 0 to 0.94 | −0.04 (−0.16 to 0.09) | 2 | 0 to 0.87 | −0.04 (−0.13 to 0.06) | 2 | 50 to 0.16 | −0.04 (−0.18 to 0.11) |
| Type of intervention | |||||||||
| Behaviour change education | 5 | 79 to 0.001 | 0.13 (−0.03 to 0.30) | 5 | 38 to 0.17 | 0.05 (−0.03 to 0.13) | 4 | 0 to 0.60 | 0.03 (−0.04 to 0.11) |
| More direct intervention | 3 | 35 to 0.21 | −0.09 (−0.25 to 0.07) | 3 | 0 to 0.94 | −0.05 (−0.12 to 0.03 | 1 | n/a | −0.11 (−0.30 to 0.08) |
| Behaviour change+direct intervention | 8 | 64 to 0.007 | 0.01 (−0.06 to 0.08) | 7 | 0 to 0.83 | −0.05 (−0.09 to −0.02) | 6 | 0 to 0.84 | −0.04 (−0.08 to 0.00) |
Significant findings are in bold font.
*Subgroup analysis included RCTs only.
HAZ, height-for-age z-score; MD, mean difference; n/a, not applicable; WAZ, weight-for-age z-score; WHZ, weight-for-height z-score.