Effect of sustained insecticide-treated bed net use on all-cause child mortality in an area of intense perennial malaria transmission in Western Kenya

We present results from a study conducted in western Kenya where all-cause child mortality was assessed among a population with high levels of sustained insecticide-treated bed net (ITN) use for up to six years. Although ITNs were associated with significant reductions in all-cause mortality among infants 1-11 months old, there was no difference in the rate of all-cause mortality among children 12-59 months old with ITNs for 2-4 years, compared historically with children from villages without ITNs, after controlling for seasonality and underlying child mortality across calendar years (adjusted hazard ratio [AHR] = 0.91, 95% confidence interval [CI] = 0.77-1.07). There was no increase in the proportion of child deaths at older ages (1.2-59 months old) of all child deaths within villages with ITNs for 5-6 years (48.1%) compared historically with villages without ITNs (47.9%), after controlling for seasonality (AHR - 1.03, P = 0.834). We find no evidence that sustained ITN use increased the risk of mortality in older children in this area of intense perennial malaria transmission.