HHS found that 19 percent of nurse aides who'd been disciplined had a prior conviction that would have shown up on a background check. Matt Rourke/AP hide caption

itoggle caption Matt Rourke/AP

Dolphin bite? There's a medical code for that. Simone Di Tonno - Annachiara Fig/iStockphoto.com hide caption

itoggle caption Simone Di Tonno - Annachiara Fig/iStockphoto.com