>Most hospital claims and bills are actually coded around day rates and DRGs, so even if the aspirin shows up as a line item it doesn't actually impact the patient's financial responsibility or the amount allowed by their health plan. (I'm not trying to defend such a confusing system, just explaining how it works.)

Yep. Hospital "bills" are a fiction. On one occasion I was presented with an "Explanation of Benefits" for a hospital stay where I was "charged" for being in two hospital rooms at the same time. As if that weren't enough I was also "charged" with having a "Pap smear"[0], even though I don't have a cervix.

I complained bitterly and after making a big stink was informed by the hospital my insurer that the items weren't actually "billed". Rather, the insurance company paid $1500/day regardless of the treatment provided.

It's disgusting!