Appendix 2—figure 1. The relationship between platelet counts and plasma PfHRP2 in severely ill African children.

The black line (shaded area) shows the estimated probability (95% confidence interval) that the plasma PfHRP2 >1000 ng/mL as a function of log₁₀ platelet count. This fit is derived from a generalised additive logistic regression model ($p<{10}^{-16}$ for the spline term), fit using the R package mgcv. The generalised additive model was fit to data from 566 African children enrolled in the FEAST trial (Maitland et al., 2011) (all the children who had both platelet counts and PfHRP2 data available). Plasma PfHRP2 >1000 ng/mL is highly discriminatory for severe malaria (Hendriksen et al., 2012).