The Technology and Methods Platform for Networked Medical Research (TMF) has published current survey results on the use of health data for research without consent, as also provided for in the GDNG (Health Data Use Act):
The GDNG provides for patient data to be shared for research and care purposes under strict data protection and security safeguards, in order to improve medical research and the quality of healthcare.
The representative survey was conducted in 2023 by the polling institute forsa with around 3,000 respondents.
For publicly funded research, 86% of respondents support sharing without their explicit consent, and only 4% consider this “very bad”.
For privately funded research, support still stands at 66%.

The recommendation is accordingly to use the situation to implement data donation and at the same time “to embed greater health data literacy and thus, in return for dropping information and consent requirements, strengthen trust in medical research”.
You can find the TMF press release on the survey at https://www.tmf-ev.de/news/einwilligungsfreie-forschungsnutzung-von-gesundheitsdaten