With drugs, physicians are treated like sales representatives by the pharmaceutical companies, who get real-time data from the pharmacies about prescriptions as they are filled. They are assigned quotas based on demographics and "education" or other programs are targeted based on how they prescribe.
I was less successful in learning exactly what information was shared re: the medical treatment, but because my employer administers hospital coverage separately from physician billing, we believe that only hospital related claims were used. The folks who I spoke to theorized that if I used an HMO, the anesthesia would have lowered my wife's "score" for further marketing.
The hospital network is good at not answering questions and I've gotten very little from them over 3 years -- I'm now thinking about lobbying a state legislator(s) about it.
They also have information about the doctors that allows them to tailor the marketing message.
This might be a good place to start learning more: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517975/
That would be a very serious breach of HIPAA.....and wow turns out I am wrong, after a quick google search, I'm now afraid you may be right- that they did not de-anonymize you but somehow botched a targeted anonymous profile. Absolutely bonkers.
https://www.scientificamerican.com/article/how-data-brokers-...