I don't know what the normal procedure is in American hospitals but at least in Finland where I live, you're 100 % the hospital's responsibility once you're there - i.e. they have to ask the right questions and even if you're dishonest with your answers they can still be held responsible, if it's something they "should" have noticed (which of course is relative). So if you go to the ER and staff ask if you've been drinking and you lie and say no and some nasty shit happens because drugs they administer have contraindications with the alcohol in your system it's a case of malpractice because they should rely on a blood sample and not a patient's word.
From the perspective of one American, that sounds insane to me. Patients absolutely must share the responsibility for receiving proper care. Holding staff responsible for a patient who directly lies about their medical history is incredibly cruel to the staff and terribly inefficient because then it would logically mean staff must test for any and all potentially relevant conditions, genetic markers, chemicals, antibodies, bacterial cultures, etc. for every patient. That would be very costly to the system. If patients expect that society has an obligation to take care of them, doesn't it seem logical that the patient has a reciprocal obligation to society to be forthright in their medical history so as to free up as many of society's resources as possible for the next, potentially sicker, patient?