Pooled Prevalence Calculator - Demonstration analyses

Background

For these demonstration analyses (except where otherwise stated), a hypothetical pooled testing strategy for the estimation of prevalence of Hendra virus in fruit bats was used. The data was based on real data for Hendra virus testing in the little red flying fox (Pteropus scapulatus) in Queensland during the period 1996 - 1999 (H. Field, pers com). During this period, 162 samples were tested from little red flying foxes, with 22 samples positive, for an estimated prevalence of 13.6% (95% CI: 8.7 - 19.8%). For these analyses, pool sizes and numbers of pools were calculated to provide 95% confidence of estimating a true prevalence of 14% with a desired precision of ± 5.5% for the various estimation methods, corresponding to the estimated prevalence and confidence interval for the original (unpooled) data. The most frequent result from simulation studies was then used to estimate the prevalence and confidence interval for each scenario.

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