The effectiveness of older insecticide-treated bed nets (ITNs) to prevent malaria infection in an area of moderate pyrethroid resistance: results from a cohort study in Malawi

Table 4 Effect of net holes on malaria incidence in a fixed cohort of 1223 children, Liwonde, Malawi April–December 2013

ITN use and hole category	Malaria infections, n	PYs at risk	Multivariate*
ITN use and hole category	Malaria infections, n	PYs at risk	Adjusted iPPY (95% CI)	Rate ratio (95% CI)	p-value	Rate ratio (95% CI)	p-value
Use of ITN with no holes	393	345	0.75 (0.55–1.02)	0.75 (0.49–1.17)	0.203	0.82 (0.69–0.98)	0.0268
Use of ITN with ≥ 1 hole of any size	376	251	0.91 (0.66–1.24)	0.91 (0.59–1.42)	0.694	Reference	–
No ITN use	25	19	0.99 (0.59–1.65)	Reference	–	–	–

ITN insecticide-treated bed net, iPPY infections per person-year
* Adjusted for age, inverse distance-weighted malaria prevalence, malaria season, number of ITNs < 300 m, altitude, household wealth index, and caregiver completion of primary school

ISSN: 1475-2875