Figure 4From: Evaluation of a rapid colorimetric field test to assess the effective life of long-lasting insecticide-treated mosquito nets in the Lao PDRPlot of mean deltamethrin surface levels for each location sampled on a net as a function of time (n = 23 matched nets) . * Deltamethrin surface concentrations were significantly different between net positions at 12 and 24 months (p < 0.001 ANOVA). Threshold proportion for net failure (EC80) is 0.14.Back to article page