Figure 2.

Receiving operating characteristic curves for the model-based geostatistics (MBG) approach applied to the spatially regulated (dashed line) and random (solid line) sampling schemes for 164 evaluation units in Ghana, with varying fraction (one-fifth or one-tenth) of locations sampled, compared with the transmission assessment survey (TAS) emulator. The number of children sampled per village is either the same as in the TAS (upper row) or increased relative to the fraction of villages sampled (lower row). The x’s indicate the performance of the TAS emulator; note that we do not change the fraction of villages or children sampled for the TAS. q is the probability threshold associated with the declaration of elimination for an evaluation unit (EU). That is, if the predictive probability that the population weighted prevalence does not exceed 2% is greater than q then elimination is declared. Abbreviations: NPV, negative predictive value; PPV, positive predictive value.