Generating a re-identification list (conversion list pseudo ID to patient ID)

Background
CTcue gives you the option to include sensitive information to your export file, such as hospital patient IDs or zip codes. This is also possible when exporting pseudonomysed medical data obtained using the data collector.

For multiple reasons, we highly recommend you to not include this sort of identifying information in the export file you create of your data collection. It can suffice to just link the datapoints to CTcue pseudo IDs.

But what if you have to refer to the health records to collect additional relevant information for your patients of interest because it could not be retrieved using CTcue? You will need some identifying information for this, such as the patient ID.

Question and solution
How can you link the CTcue pseudo ID to identifying information such as eg. hospital patient ID, date of birth or zip code in a file separate from the export file containing medical data collected using CTcue?

We advice you to generate a conversion list, or a re-identification list. This list can contain both the pseudo ID, patient ID and any other identifying information but should not contain any other data. We will explain how to do this below.

Step 1: generating the re-identification/conversion list.
Remember: every time your cohort of included and excluded patients changes, you will have to generate a new conversion list.

1. In the patient cohort menu, move your patients of interest from the 'search results' tab to 'included' or 'excluded'.
   
   Example: all patients added to 'included':
   
2. Go to the 'export' menu.
3. In the 'export selection' dropdown menu, select 'patient cohorts'. This way, only information from the patien finder module will be exported. This export will not contain any medical data.
4. In the 'choose patient cohorts in the export' menu, select 'included'.
   The data collector module only retrieves information on patients in the 'included' tab, therefore these are the only ones to select for your conversion list.
5. In the 'sensitive data' menu, switch on the 'add identifiers to my export'.
   Select which sensitive information to include in the export using the tick boxes.
6. Hit the 'Export patients' button.
   
   Screenshot of export settings:
   
7. Your export file will contain CTcue pseudo ID and, using the example above, patient ID and date of birth of all patients included in the patient cohort menu. Your search criteria built in the 'criteria' menu will be listed per column and the export will list if patients are valid, invalid or undecided, depending on what you selected during the patient cohort validation process.
   
   Example of the conversion file, based on our fake patient records:
   

Store this re-identification or conversion list separate from the export file containing the medical data collected for these patients.

Step 2: Exporting data collection without identifying information
When you've built your questions in the data collector and are happy with the data retrieved and listed in the data validation table, you can continue to export this data without identifying information as follows.

1. Go to the 'export' menu.
2. Set the 'export selection' to 'data collection' using the dropdown menu.
3. In the 'sensitive data' menu, switch off the 'add identifiers to my export' slider.
   
   
   

Your export file will only contain pseudo IDs, sensitive information will not be included.

Concluding remarks
Please be aware that to enhance security, you should store both files in separate directories, or protect the conversion/re-identification file with a good password.