You can call the hospital's billing department. I had this same thing happen to me. I was a passenger in a wreck and the driver's insurance just didn't cover anything and no one said anything. Months and months go by and I figure out it's in collections and no one said said a thing to me.
The end result: Ultimately, it's your fault for not paying your bill, so you can't get the blemish erased from your report even though the circumstances are ridiculous (I tried). The billing department told me how to pay it, so it was changed on my credit report to at least say "paid" next to it, which is better, but still not great. Then, yeah, waited 7 years or however long for it to finally disappear.
So, sorry about your bad luck, but I think this just must be something hospitals are terrible at.
