Recall spreadsheets and AI patient data: what a billing and recall sheet gives away in ChatGPT or Claude.

Practice managers keep recall lists in spreadsheets, because the practice software exports to them and a spreadsheet is quick to filter. Someone then uploads the sheet to ChatGPT or Claude to draft recall messages, find overdue patients or check a formula. The sheet is a table of patient names against birth dates, mobile numbers, Medicare item numbers, condition codes and a notes column, repeated for every patient on the list. This page marks what a routine billing and recall sheet exposes under the Privacy Act and the NSW health records law, and shows how the same list is worked on Ermos inside the practice.

The billing and recall spreadsheet

Kept by the practice manager or recall nurse from the practice software, to chase overdue reviews, plan recalls and reconcile billing. It is often shared by email, which is how it reaches an AI tool.

An invented spreadsheet. All patients are fictional and the phone numbers are placeholders. Hover or tap any highlighted item for the analysis; the full list is below.

What leaves the practice

1. 1
   Patient names and dates of birth

   Ten names against birth dates. Personal information, and because the practice collected it in providing a health service, health information under section 6FA(b) of the Privacy Act. Privacy Act guide.

2. 2
   Mobile numbers

   Direct contact details for every patient on the list. Personal information, and the starting point for phishing and impersonation. Privacy Act guide.

3. 3
   Medicare item numbers

   Which service was billed to which patient. A single number is public, but against a name item 2715 reveals a mental health plan and 965 a chronic condition management plan.

4. 4
   Last seen and recall dates

   When each patient was seen and when they are due back. It shows treatment schedules and when a person will next be at the practice.

5. 5
   Condition codes

   A code per patient for the problem managed, from diabetes to depression, pregnancy, contraception for a 16-year-old and HIV. Health information is sensitive information under the Privacy Act, and these are among its most sensitive entries. Patient data guide.

6. 6
   The notes column

   Free text with the most candid detail: a complaint, a custody arrangement, an undisclosed pregnancy, a teenager whose parents are unaware. Instructions about who must not be told, which the practice has to be able to follow. Patient data guide.

7. 7
   The recall formula

   A date test with no patient information in it. The same formula can be shared safely, and the sheet it sits in cannot.

8. 8
   Other tabs, hidden columns and file properties

   A spreadsheet file generally carries more than the visible tab: other sheets, hidden columns, cell comments and properties such as the author. Uploading the file sends all of it, including what is off screen.

What happens in Frontier Models (ChatGPT, Claude)

• The whole document is transmitted to the provider’s servers. On personal plans the user cannot choose where it is stored or processed, and for the major providers that has generally meant outside Australia, under that country’s legal process. Some business plans offer storage in Australia, but the provider still receives the content.
• On consumer tiers, prompts can be retained and used to train future models.
• The provider’s staff and systems can reach the content under the provider’s own policies.
• Once sent, the practice no longer controls it. Retention and deletion happen on the provider’s terms.

The same document on Ermos

Part of AI data leakage in healthcare practices. See how this works in practice: Recall letters on Ermos.

Common questions