Hospitals are changing the way they operate — no pun intended — and its putting some patients’ health at risk. It used to be common practice for hospitals and other medical facilities to calculate costs and send bills to patients after they’d completed the important part, i.e. treating the patient. That’s less true today than it used to be, according to The Wall Street Journal. Collecting payment in advance is more and more common at medical centers, and while that saves hospitals time and money collecting on bills later, it means that some patients don’t get the care they need when they nee…