I have followed the hospital charges for a long time. The insurance companies have driven the minimum costs out of sight.
Around 1980, the college I was attending was given a new computer system, and one year of maintenance. The students were allowed unlimited usage. The programming instructor told me one night I had just used more CPU time on a simple program than she had used for her entire college degree.
The next year, each month each department got a bill for it's usage percentage of total operating and maintenance costs of the system. After the screams of rage subsided, each department established maximum usage limits. The price per minute of usage, that is, total costs divided by minutes of usage, exploded, and the departments again shoved maximum usage down and down, until cost per minute became outrageous. Yet, most of the time the system was idle.
The incremental cost of that CPU running all the time was very small. But, a very cheap system became prohibitively expensive, thanks to the bean counter stupidity. (I am a certified bean counter, so feel free to be nasty about it.)
Though it isn't exactly the same, a somewhat similar thing happened to hospital care. A lot of people went to the hospital, and daily costs were reasonable. Then, insurance companies decided to save money be reducing hospital usage. As the usage went down and down, the cost per visit or day also exploded.
This is because a hospital has to have a lot of stuff on hand, no matter how much it is used. Labs; cancer treatment equipment; surgery; pharmacies; x-ray labs; MRI; and things I don't even know.
As usage goes down, the cost goes up. And, so desperately the insurance companies try to reduce further the usage.
Imagine what a car repair shop would be like if your mechanics were only busy 10% of the time. Of course, most shops would soon go out of business, with $1000 an hour billing. The problem is, there are geographic limits on hospitals going out of business and consolidating. No one wants to travel 250 miles to the nearest hospital.