Chapter 26 Simple Undetected Prevalence Estimator Model

26.1 What is the Simple Undetected Prevalence Estimator Model?

The Simple Undetected Prevalence Estimator estimates the maximum underlying and unseen prevalence of CWD after sampling has been completed and no positive cases were found.

IMPORTANT: This tool does not consider age, sex, or source of samples, which are known to influence prevalence computations. If the sample data of interest contains information on age, sex, and source, consider using the Prevalence Estimator Data Export.

26.2 What Questions Does it Answer?

Question 1. What is the maximum possible unseen prevalence of CWD in each sub-administrative area given the information in our sampling data? The Simple Undetected Prevalence Estimator Model can be used after sampling when no positive cases are found to estimate the maximum possible prevalence of CWD in each sub-administrative area.

Question 2. What is the maximum possible unseen prevalence of CWD in each sub-administrative area if we adopt the sampling quotas from a non-statistical model? The Simple Undetected Prevalence Estimator Model can be used in conjunction with a non-statistical sampling quotas model to see the level of assurances in CWD status may arise if the quotas were to be followed without finding a positive case.

26.3 Output Details

Three maps containing the the maximum underlying unseen prevalence based on Bayesian, Frequentist, and Frequentist with sensitivity approaches.

26.4 Abbreviated Tutorial

  1. Run the Simple Undetected Prevalence Estimator Model from the CWD Data Warehouse.
  2. Click through the maps to explore the maximum underlying prevalence in each area given sample effort.

26.5 Parameters Needed to Execute the Model

  • Model type: Select ‘Simple Undetected Prevalence Estimator Model’ from the drop-down list.

  • Reference name: Label the run.

  • (Optional) Applicable season-year: Label the season-year of the run to assist in documentation.

  • (Optional) Notes: Enter any remarks about the run.

  • Species: Select the species of interest for estimation. Underlying prevalence can only be estimated for one species at a time.

  • Season-year: Select the season-year to be used in the estimation. Please note that underlying prevalence can be estimated for only one season at a time.