Table 2.

Diarrheal disease prevalence and intervention effect estimates

Study arm	May 2010 diarrhea period prevalence (%)	June 2010 diarrhea period prevalence (%)	July 2010 diarrhea period prevalence (%)	Diarrhea prevalence over 12-week period (%)	Diarrhea prevalence ratio (95% CI)*	P value†
Control (N = 220)	49	39	42	43	−	−
WASH BCC (N = 246)	61	20	14	30	0.71 (0.59–0.86)	0.0857
Filter (N = 235)	10	10	6	9	0.21 (0.15–0.30)	0.0286
Filter and WASH BCC (N = 203)	16	11	9	12	0.27 (0.22–0.34)	0.0286

^*Calculated using a GEE using a Poisson distribution adjusted for study clusters.

^†P values were calculated using Wilcoxon scores (rank sums) with the exact method (two sided).