Table 3.

Summary of first-time and overall (total new) malaria incidence during the study

	First-time infection			Overall (total new) infections
	All clusters	Subgroup 1*	Subgroup 2†	All clusters	Subgroup 1*	Subgroup 2†
	SR: placebo
No. of clusters	12:12	10:9	6:6	12:12	10:9	6:6
No. of households	665:667	557:500	335:335	665:667	557:500	335:335
No. of infections	134:164	130:158	93:140	253:439	249:433	196:408
Person years	1079:1032	873:722	506:444	1216:1216	1015:909	609:607
Incidence rate (per person-year)	0.124:0.159	0.149:0.219	0.184:0.315	0.208:0.361	0.245:0.476	0.322:0.672
Hazard ratio (90% CI)	0.723 (0.431,1.213)	0.64 (0.299, 1.367)	0.447 (0.302, 0.664)	0.687 (0.426,1.108)	0.591 (0.382, 0.914)	0.344 (0.233, 0.508)
Protective efficacy (%) (90% CI)	27.7 (−21.3, 56.9)	33.3 (−7.8, 58.7)	55.3 (33.6, 69.9)	31.3 (−10.8, 57.4)	40.9 (8.61, 61.8)	65.6 (49.2, 76.7)
One-sided P-value	0.151	0.083	0.0004	0.098	0.0236	< 0.0001

SR = spatial repellent.

^*Subgroup 1: clusters with nonzero incidence during intervention.

^†Subgroup 2: clusters with entomology data collected (moderate to high risk of infection).