The Simulation Parameters

The simulation model can be configured at two levels: first, it can be configured by means of a spreadsheet front-end. Second, more detailed parameters can be configured directly in the CPN Tools model.

Configurations via Spreadsheet Front-End

TXT files with name “TokensModel[Province][Year].txt” configure the CPN Tools model with information about the patient characteristics and ensure that patients are generated according to the specifics of a geographical region (preferably a province but a country could be used as a region too).  As a concrete example, we provide files that configure the model to produce patients for the province of Limburg in years 2013, 2025 and 2040. However, similar files can be generated for other countries and provinces, using a spreadsheet tool such as Microsoft Excel.

Spreadsheet-tab1

The subsequent steps should be followed to make a new TXT input file which can be processed by the executable CPN Tools model:

  1. In Excel file “TokensModel [Region].xlsx” (e.g., “TokensModel Limburg.xlsx”), open the subtab “Background Information”.
  2. In each orange cell, the input asked should be written as mentioned for the cell:
    • % Dialysis patients per age group;
    • % Initial eGFR levels over age groups;
    • % Dialysis patients per province;
    • Total number of dialysis patients per year, including patients that receive a pre-emptive living donor
  3. Verify the grey cells.
  4. The output values needed are automatically copied to the subtab “LookupTable”. Check whether the grey cells ranges between 0 and 1.
  5. The province name can be written in the first column of the “LookupTable”.
  6. Copy the output cells AG2-AG10 and only paste the values in the subtab “Token”.
  7. Save the “Token” worksheet as Text (MS-DOS) file (.txt) as “TokensModelProvinceYear” and save the whole document as Excel (.xls) file.
  8. Fine-tune the generated TXT file as follows: change the f value in the first row in 0.0 (e.g. from 1`{egfr=l100_30,a=a0_44,p=Limburg,f=0,t=0.1137003}++ to 1`{egfr=l100_30,a=a0_44,p=Limburg,f=0.0,t=0.1137003}++) and the t value in the last row to 1.0 (e.g. from 1`{egfr=l15_9,a=a65_,p=Limburg,f=0.9559909,t=1} to 1`{egfr=l15_9,a=a65_,p=Limburg,f=0.9559909,t=1.0}).
  9. Store this .txt file in the same folder as the CPN Model.  Otherwise, it will not be picked up by the simulation runs.

Configurations in CPN Tools

Several other parameters can be adjusted, still without changing the model structure. Below, per subpage of the CPN Tools model, the input parameters that should be included are mentioned.

Generator

  • TokensModels: The file names of the three TokensModels should be inserted. In the left part of the page, you can see three times a text with the following structure “TokensModelProvinceYear” next to the arrow linking to the place “Table of Patienttypes”. Please, make sure that the names of the TokensModel .txt  files are exactly the same here and insert the right years.
  • Arrival rate of patients: The number of patients per year that should be generated can be inserted in the patientarritvals() function. Please, in the menu, open the following path “Declarations –>Functions –> fun patientarrivals” and replace the current 211.32 by the new number of patients per year. Make sure this value is a real number.

 Postmortal donor generator

  • Number of postmortal donors: The expected number of postmortal donors per year can be inserted in the genpostmortaldonor() function. Please, in the menu open the following path “Declarations –>Functions –> fun patientarrivals” and replace the current 37.99 by the new number of postmortal donors in 2013, replace the current 49.69 by the new number of postmortal donors in 2025 and replace the current 58.96 by the new number of postmortal donors in 2014. Make sure that all these values are real numbers.

Treatment

  • Capacity of centers: The total capacity of hemodialysis centers per province can be changed in this subpage. Replace the current capacity of 954 patients in one province by the new capacity. Make sure this number is an integer value.

 

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