# 1-Stage Freedom analysis

Use these utilities to assist with planning and analysis of simple 1-stage surveys to demonstrate disease freedom. Methods are appropriate for sampling units (animals, fish, plants, etc) to demonstrate cluster (herd, flock, farm, tank, etc) freedom, or for either individuals or clusters to demonstrate population freedom. All methods assume representative sampling of units from the population and methods are included for large (or unknown) and finite (known) population size. Most of the options (except where noted) assume perfect (100%) test specificity.

Click here for some important formulae for freedom analyses.

## Assuming perfect test specificity (100%)

### Sample size calculation

Use these options to estimate required sample size assuming **perfect** test specificity:

### Population sensitivity calculation (SeH or SSe)

Use these options to calculate cluster or population-level sensitivity assuming **perfect** test specificity:

- Population sensitivity assuming perfect test specificity (replaces previous options for large and finite populations)
- Population sensitivity for varying unit sensitivity
- Population sensitivity using pooled sampling

## Allowing for imperfect test specificity (<100%)

### Sample size calculation

Use these options to estimate required sample size assuming **imperfect** test specificity:

### Population sensitivity with imperfect test specificity

Use these options to calculate cluster or population-level sensitivity assuming **imperfect** test specificity: