Two-stage lot quality assurance sampling framework for monitoring and evaluation of neglected tropical diseases, allowing for imperfect diagnostics and spatial heterogeneity
Fig 8
The relative total survey cost of imperfect diagnostic tests with varying sample throughput and reagent costs.
The contour lines illustrate the total survey cost when applying imperfect diagnostic tests with varying sample throughput and reagent cost to test one sample relative to the total cost of a survey based on the hypothetical reference diagnostic test with the sample throughput (9 samples per hour per person) and cost characteristics (1.38 US$ reagent test cost) of single Kato-Katz thick smear. We considered three hypothetical diagnostic tests Dt3 (reference diagnostic test; Panel A), Dt2 (Panel B), and Dt3 (Panel C), each with a different diagnostic performance (). The intra-cluster correlation ρi was set at 0.02 and the number of clusters at 10. The number of subjects per cluster and the total survey cost was defined as the minimum required number of subjects per cluster and minimal cost required for adequate decision-making (Eovertreat = 25% and Eundertreat = 5%) around a program prevalence threshold of 2%, with the grey zone defined as T±50% (LL = 1% and UL = 3%). All three panels were based on 10,000 Monte Carlo simulations.