Increased proportions of outdoor feeding among residual malaria vector populations following increased use of insecticide-treated nets in rural Tanzania

Table 2 The proportion of human contact with mosquito bites occurring indoors (π_i) in the Kilombero Valley, Tanzania during 1997, 2004 and 2009.

Year	Proportion ± s.e.	n/N^a	Odds ratio [95% CI]	p value
*Anopheles gambiae s.l*.
1997^b	0.997 ± 0.002	366/367	1.00	NA
2004	0.926 ± 0.004	3,622/3,912	0.928 [0.797 - 1.080]	0.337
2009	0.820 ± 0.008	1,964/2,395	0.822 [0.703 - 0.962]	0.0143
Overall influence of Year		5,952/6,674	NA	0.0019
*Anopheles funestus*
1997^b	1.000 ± 0.000	210/210	1.00	NA
2004	0.761 ± 0.063	35/46	0.761 [0.471 - 1.229]	0.264
2009	0.505 ± 0.048	54/107	0.504 [0.345 - 0.737]	0.0004
Overall influence of Year		299/363	NA	0.0014

Proportions for each survey period are compared using GLMMs with a binomial distribution, a categorical explanatory variable for study year and a random factor for date.
^a Calculated as: (I_{21→05 hrs})/(I_{21→05 hrs} + O_{18,19,20,06 hrs})
^b Formed reference category for GLMM

ISSN: 1475-2875