Here in Canada , fax is widely used in the medical field in the same way. One could not run a medical office or organization of any kind or size without a fax line. I have heard the legal sector is likewise reliant.

In a functional way I don't know it's wrong to say email is less secure. It's not that they don't want to buy computers. Everyone has freaking computers; gimme a break. Email (1980s tech) is almost as antiquated as fax machines (1970s) and has many vulnerabilities. There is no way in hell your dermatologist is getting to a PGP party anytime soon. They probably use the same password for every account and that password is probably their name or something and have been using the same one for 20 years. The password is known by perhaps dozens of current and former employees. The email is downloaded onto devices which may not use encryption for storage. They don't install windows patches but they do install random shit from the internet. And so on. OTOH, who is hacking fax machines?

The solution isn't to move to email, it's to hop past email to use a natively encrypted technology with security enforced by a service provider. If the public funders would step up to support a Free Software solution this could have been done already. But instead they fund this and that proprietary system that doesn't work out, then have to start from scratch in a few years. There hasn't been incentive to create interoperability. Just a bunch of privately-held companies frothing at the mouth to make all the $$$ they see in the health care industries competing with each other.

BTW I have heard that fax machines are still in wide use in the US medical field also, but it depends what system you are in. E.g "kaiser" system has it's own internal comms system they use and so on. But inter-system, fax will always be the lowest common denominator.