If I am working on a project for somebody, that person gets billed about $150 per hour for my service. That cost includes my salary, equipment, and overhead. If somebody comes into my office, I will offer them a bottle of water or a soda. They won't be charged for the beverage. Let's say the total cost of the project is $200,000. The hospital equivalent would be me charging $50,000 for the service, $50 for the beverage, $15 per gallon of fuel used, $25,000 for vehicle service fees, $1,000 for report binding, etc. The final cost would still end up being $200,000, but anybody who sees that bill is going to get pissed off, and rightfully so.
People in a hospital generally don't feel well. It doesn't make sense to give them a bill that encourages them to not use tissues or take pain pills. It would make a lot more sense to me if hospitals just had a blanket charge for their service that included things like tylenol, ice, and tissues.