I've gotten multiple calls from "businesses" like this and they're headhunters for the sleazy lawyers advertising class action lawsuits on TV. They are calling because you have either gotten a prescription that could be used for the conditions they're calling about or you've bought an OCT item from a store that uses loyalty cards that relates to the conditions. If you've bought something with your credit or debit card and that "anonymous information" is sold by cross referencing that to public records they have your information. Your prescriptions are supposed to be covered by HIPPA but many pharmacies (and some doctors) have "Opt Out" exceptions in the information they know 99% of people don't read that allows them to pass along your information to "related third parties" that offer products that may be of benefit to your health issues based on your prescriptions.
For the most part, this is sold to the drug manufacturers so they can send coupons or information on how to apply for their discount programs to people without insurance. But, as with all information these days it's compiled by data mining companies and they're only interested in how much money they can make selling your information. Because they're allowed a certain margin of error and they use multiple streams of data collection it's almost impossible to prove that they've violated HIPPA.
My number ends in 00 so I plan to answer with "State Department of Telecommunications Fraud. This number has been tagged and traced in case of a criminal inquiry. How May I help you?"
I truly enjoy screwing with asshats like this! But I hope this tells you how they get your information and why they're calling. I heard that headhunters for the mesothelioma class action lawsuits get up to $10,000 per litigant they refer. With a $30 billion dollars trust and very little actual litigation work to do to file a claim now that the trust is established, a lawyer can make 1/3 of $100,000 at the bare minimum for two hours of work done by an associate who gets paid $15 an hour. It's just another growth industry to be exploited.