Sample Size Calculations for Surveys to Substantiate Freedom of Populations from Infectious Agents

摘要: Summary.  We develop a Bayesian approach to sample size computations for surveys designed provide evidence of freedom from disease or an infectious agent. A population is considered “disease-free” when the prevalence probability less than some threshold value. Prior distributions are specified diagnostic test sensitivity and specificity we null hypothesis that below threshold. Sample developed using hypergeometric sampling finite populations binomial infinite populations. normal approximation also developed. Our procedures compared with frequentist methods Cameron Baldock (1998a, Preventive Veterinary Medicine34, 1–17.) example foot-and-mouth disease. User-friendly programs calculation analysis survey data available at http://www.epi.ucdavis.edu/diagnostictests/.