High-end is generally said to be high-end is possible, but many times with top, VIP is also persuasive
As for the medical, can not be directly translated into medical treatment, which is the error of using the network translation, in fact, here contains the meaning of service, so the general translation for the healthcare, medical service, health service is better.
Payment is usually made with direct-pay, but also with direct-billing
As for the organization, it is actually more of a medical network meaning here, so it should be translated as medical-network, service network.
Well, how it is ultimately put together depends on what you say in this sentence. sentence in this article or the whole paragraph to decide.
Translation is not about combining and copying words!