Table 3.

Observed vs. expected standard deviations of diarrhea prevalence by study

Study	Number of observations	Mean diarrhea prevalence	Observed standard deviation	Expected standard deviation	% of observed standard deviation expected as sampling error	Coefficient of variation (%)
Weekly
Soap health	20372	0.058	0.195	0.089	45	334
Floc health	17764	0.079	0.223	0.102	46	281
Long-term practices	14932	0.049	0.183	0.082	45	372
Monthly*
Soap health	4217	0.060	0.122	0.043	35	202
Floc health	3752	0.081	0.129	0.049	38	158
Long-term practices	3130	0.050	0.118	0.040	33	237
Pakistan DHS†
1991/2	5422	0.134	0.341	0.091	27	254
2006/7	8391	0.224	0.417	0.111	27	186

^*Child months with fewer than 4 weeks of observation were excluded from this analysis.

^†Demographic and Health Survey.