Input Values
Submit Data
Note: this now requires inclusion of a header row in the data


Note: This page now accepts data where either a comma (,) or point (.) is used as the decimal separator.
Use this page to calculate the confidence of country or area freedom from disease/infection
 over multiple time periods
 when the sensitivity of the surveillance system in each time period is known (or can be estimated)
 when the risk of introduction of disease in each time period is known (or can be estimated)
 when the prior confidence of freedom can be estimated
Data Format
To submit data, enter it into three columns of a spreadsheet, copy it and paste it into the text box below. The format requirements are:
 three columns only
 include a header of column names (Note: this has changed from previously when a header row was not required)
 first column: Period (a number or text label to describe each period, eg 2001, 2003...)
 second column: System sensitivity (between 0 and 1  i.e. not as a percentage)
 third column: Risk of introduction of disease during each time period (between 0 and 1)
Outputs
Outputs are a table and plot of the following values:
 System sensitivity for each time period (input);
 Posterior confidence of freedom at the end of each time period;
 Probability of introduction during each time period (input);
 Prior probability of freedom for each time period (after adjusting for possible introduction during the period); and
 Equilibrium confidence of freedom  the stable maximum (or minimum) value for confidence of freedom for given SSe
and PIntro for each time period (see Watkinset al., 2009. An evaluation of the sensitivity of acute flaccid paralysis surveillance for poliovirus infection in Australia. BMC Infectious Diseases, 9, 162).
