This utility calculates a population or cluster level sensitivity for a survey. This is the probability
(or level of confidence) that one or more positive units would be detected if the disease was present at a prevalence
greater than or equal to the specified design prevalence.
For these calculations unit specificity is assumed to be 100%.
For calculating cluster (herd, flock, etc) sensitivity, enter test sensitivity and unitlevel design prevalence or
for population level sensitivity enter clusterlevel (herd) sensitivity and design prevalence.
Calculations use the hypergeometric approximation if population size is provided, or binomial method if population size is not specified.
Inputs are:
 Design prevalence as either a proportion or an integer number of units (animals for cluster level sensitivity and clusters for populationlevel sensitivity);
 Unit sensitivity (test sensitivity to calculate cluster (herd) sensitivity or cluster (herd) sensitivity tocalculate population sensitivit;
 Sample size  the number of units sampled (animals or clusters); and
 Population size (optional if design prevalence is specified as a proportion, required if design prevalence is a number of units). Leave population size blank if not known.
Outputs are:
 Populationlevel sensitivity for the given sample size, design prevalence and unit sensitivity; and
 A table and graph of populationlevel sensitivity values for varying population and sample sizes
and the given design prevalence and unit sensitivity.
