Evaluating the effectiveness of IPTi on malaria using routine health information from sentinel health centres in southern Tanzania

Table 4 Incidence of first or only and all OPD attendances, and incidence of attendance in all time at risk, and within 28 days of IPTi dose one

	Intervention Area			Comparison Area			Effect
Intention to treat *	Events	PYAR	Rate	Events	PYAR	Rate	RR (95% CI)	p value	PE (95% CI)
Health centre attendance (first or only)
crude	2160	1535.3	1.407	2067	1434.4	1.441	0.97 (0.92-1.04)	0.417	3% (-4%,8%)
adjusted ^‡							1.04 (0.75-1.45)	0.795	-4% (-45%,25%)
Health centre attendances (all episodes)
crude	3631	1810.5	2.005	3425	1699.3	2.015	0.99 (0.95-1.04)	0.834	1% (-4%,5%)
adjusted ^† ^‡							1.05 (0.75-1.48)	0.736	-5% (-48%,25%)
	IPTi Intervention Area			Corresponding EPI vaccine Comparison Area			Effect
Per protocol **	Events	PYAR	Rate	Events	PYAR	Rate	RR (95% CI)	p value	PE (95% CI)
Health centre attendances (all episodes) in ATAR since IPTi dose
IPTi dose 1
crude	1109	565.2	1.960	1082	466.6	2.317	0.84 (0.78-0.92)	0.001	16% (8%,22%)
adjusted ^† ^‡							0.98 (0.69-1.38)	0.907	2% (-38%,31%)
Health centre attendance (all episodes) within 28 days of IPTi dose
IPTi dose 1
crude	106	93.7	1.131	125	80.3	1.556	0.73 (0.56-0.94)	0.016	27% (6%,44%)
adjusted ^† ^‡							0.82 (0.48-1.40)	0.421	18% (-40%,52%)

* Intention to treat analyses comparing IPTi intervention and comparison areas
** Per protocol analyses comparing children who received IPTi in intervention areas to those that received corresponding EPI vaccines in comparison areas
EPI = expanded programme on immunization, PAYR = person years at risk, ATAR = all time at risk, RR = rate ratio, CI = confidence interval, PE = protective efficacy
^† Results adjusted for clustering within children for multiple episodes of all-cause health centre attendance using Poisson random effects modeling
^‡ Using intervention and comparison area mean rate, unpaired t test p value and approximate 95% CI that adjust for clustering by health centre

ISSN: 1475-2875