The aim of this study was to estimate the power of a badger vaccine field trial using simulation techniques. The effects of sample size, sensitivity and specificity of the diagnostic test, transmission rate between unvaccinated badgers, Vaccine Efficacy for Susceptibility (VES) and Vaccine Efficacy for Infectiousness (VEI) on study power were determined. The most striking result was the large effect of the specificity of the diagnostic test on study power. Sample size had a small effect on power. Study power increased with increasing transmission rate between non-vaccinated badgers. Changes in VES had a higher impact on power than changes in VEI. In summary, study power in group randomized trials depends not only on sample size but on many other parameters. In the current vaccine trial, power was highly dependent on the specificity of the diagnostic test. Therefore, it is critical that the diagnostic test used in the badger vaccine trial is optimized to maximise test specificity.
|Title of host publication||Proceedings of the Society for Veterinary Epidemiology and Preventive Medicine, Leipzig, Germany, 23-25 March 2011|
|Editors||C. Fourichon, D.U. Pfeiffer|
|Publication status||Published - 2011|
|Event||Society for Veterinary Epidemiology and Preventive Medicine, Leipzig, Germany - |
Duration: 23 Mar 2011 → 25 Mar 2011
|Conference||Society for Veterinary Epidemiology and Preventive Medicine, Leipzig, Germany|
|Period||23/03/11 → 25/03/11|