Simulate sampling for fixed pool size and assumed perfect test

Input Values

  

Introduction

This utility simulates sampling and prevalence estimation for alternative pooling strategies for an assumed prevalence value and for a specified level of confidence. The program runs multiple iterations of sampling and estimation and calculates the mean prevalence and estimated bias across all iterations. See the User Guide for more details. See demonstration analysis

This method estimates prevalence using a method that assumes that test sensitivity and specificity are both 100%. However, if the true sensivitity and specificity of the test are likely to be less than 100% estimates of the true values can be entered to investigate the potential impact of this assumption being invalid on the resulting prevalence estimate.

Inputs

Required inputs for this program are:

  • assumed true prevalence of infection - between 0 and 1;
  • estimates of likely true test sensitivity and specificity - between 0 and 1;
  • the desired level of confidence - between 0 and 1;
  • the number of iterations to simulate - a positive integer; and
  • the size and number of pools to be tested for each strategy to be simulated. This data should be copied and pasted from a spreadsheet format as described below.

Outputs

Outputs are summarised across all iterations for each strategy entered and presented in a summary table. The main outputs are:

In addition, detailed results for all iterations for each strategy can be downloaded as a text file, and histograms of the prevalence estimates can be viewed by clicking on the appropriate icons in the summary results table.

Note:

Data for pool sizes and associated numbers of pools tested should be pasted into the data submission area. You can enter any number of scenarios to simulate, with a new row required for each scenario. You must enter at least two columns of data, labeled "PoolSize" and "Pools". Include a header row containing the names.

Design parameters:
Assumed true prevalence:
True test sensitivity:
True test specificity:
Desired Confidence level:
Simulation details:
Number of iterations:

Data:

This module takes several minutes to run, depending on numbers of scenarios and iterations requested so that your web browser could time-out. If you have problems, enter your email address and an email will be sent to you with a link to the results.

Paste data in the space below. Data columns can be in any order but must include columns labeled "Poolsize" and "Pools". A header row specifying column names must also be included.
Download example data


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