Table 3.

Incidence of clinical malaria cases

			Mean malaria incidence per person-year (95% CI)*					Effect of net use and resistance in all five countries combined†			Effect of net use and resistance in Benin, Cameroon, Kenya, and India combined†
			Benin	Cameroon‡	Kenya	Sudan	India	Total resistance observations	Unadjusted rate ratio (95% CI)	Adjusted§ rate ratio (95% CI)	Total resistance observations	Unadjusted rate ratio (95% CI)	Adjusted§ rate ratio (95% CI)
Overall incidence			0·48 (0·39–0·59) [715/1496]	1·33 (1·11–1·60) [1509/1132]	0·82 (0·68–1·00) [4780/5798]	0·033 (0·024–0·044) [1322/40 583]	0·030 (0·020–0·044) [254/8555]	..	..	..	..	..	..
Caregiver-reported use of net on the previous night
	Non-net use		0·70 (0·51–0·95) [92/132]	..	1·38 (1·02–1·87) [339/245]	0·024 (0·018–0·033) [384/15 848]	0·090 (0·055–0·147) [89/987]	588	1 (ref)	1 (ref)	397	1 (ref)	1 (ref)
	Net use		0·46 (0·36–0·57) [623/1365]	..	0·80 (0·65–0·97) [4331/5442]	0·038 (0·038–0·052) [938/24 735]	0·023 (0·016–0·033) [165/7319]	588	0·65 (0·42–1·01); p=0·055	0·62 (0·41–0·94); p=0·024	397	0·49 (0·34–0·70); p<0·0001	0·48 (0·33–0·69); p<0·0001
Insecticide resistance
	Low resistance (mortality ≥78·57%)		0·63 (0·48–0·85) [312/495]	1·21 (0·80–1·85) [530/437]	0·83 (0·66–1·04) [1869/2257]	0·037 (0·023–0·058) [434/11 852]	0·030 (0·019–0·046) [185/6244]	683	1 (ref)	1 (ref)	492	1 (ref)	1 (ref)
	High resistance (mortality <78·57%)		0·40 (0·32–0·50) [403/1001]	1·41 (1·13–1·75) [979/696]	0·82 (0·63–1·07) [2911/3541]	0·031 (0·023–0·042) [888/28 731]	0·030 (0·015–0·061) [69/2311]	683	0·93 (0·73–1·18); p=0·557	0·89 (0·72–1·10); p=0·298	492	0·97 (0·74–1·27); p=0·828	0·91 (0·73–1·14); p=0·399
	Effect per 10% reduction in bioassay mortality		..	..	..	..	..	683	0·95 (0·95–1·00); p=0·056	0·94 (0·89–0·99); p=0·018	492	0·95 (0·89–1·02); p=0·132	0·93 (0·88–0·99); p=0·029
	Effect per 10% reduction in bioassay mortality after removal of outliers		..	..	..	..	..	679	0·95 (0·90–1·0); p=0·064	0·95 (0·89–1·02) p=0·151	488	0·94 (0·89–0·99); p=0·031	0·94 (0·88–1·00); p=0·0475
Stratifying by resistance (interaction)
	In low resistance areas (mortality ≥78·57%)
		Non-net use	0·74 (0·52–1·06) [67/91]	..	1·60 (1·09–2·35) [114/71]	0·031 (0·019–0·052) [137/4414]	0·099 (0·056–0·177) [70/707]	307	1 (ref)	1 (ref)	251	1 (ref)	1 (ref)
		Net use	0·61 (0·44–0·84) [245/405]	..	0·80 (0·36–0·70) [1698/2120]	0·040 (0·024–0·066) [297/7438]	0·021 (0·014–0·032) [115/5354]	307	0·59 (0·37–0·94); p=0·027	0·59 (0·38–0·90); p=0·015	251	0·45 (0·27–0·74); p=0·002	0·44 (0·27–0·72); p=0·001
In high resistance areas (mortality <78·57%)
		Non-net users	0·61 (0·39–0·96) [25/41]	..	1·29 (0·85–1·97) [225/174]	0·022 (0·015–0·031) [247/11 434]	0·068 (0·031–0·150) [19/281]	281	1 (ref)	1 (ref)	146	1 (ref)	1 (ref)
		Net users	0·39 (0·32–0·49) [378/960]	..	0·79 (0·60–1·04) [2633/3322]	0·037 (0·027–0·052) [641/17 297]	0·025 (0·011–0·055) [50/1964]	281	0·62 (0·94–10·04); p=0·068	0·51 (0·27–0·98); p=0·042	146	0·43 (0·27–0·67); p<0·0001	0·35 (0·20–0·61); p<0·0001
	Interaction parameter (net use by high resistance)		..	..	..	..	..	..	0·95 (0·48–1·90); p=0·942	1·15 (0·53–2·47); p=0·860	..	1·04 (0·53–2·07); p=0·947	1·28 (0·61–2·67); p=0·737

^*Absolute numbers for incidence (cases/child-years) are given in square brackets.

^†Excluding Cameroon for comparisons involving net use.

^‡Use of nets was an inclusion criterion for the cohort study in Cameroon, so the data do not provide a comparison of net users versus non-net users.

^§Adjusted for age, district, calendar month, and, in the case of Sudan, indoor residual spraying.