Depends on what you take the word efficient to mean, even at the top end I don't find medical care very efficient. Basic procedures can be very expensive for my insurance company. I'll define efficient here as results to cost. In the US, there are groups at every level between patient, doctor, insurance and big pharma where often their goal is to create inefficiencies because the less efficient the treatment, the more money make. Look at something like insurance billing codes; I have a friend who's entire business is telling Dr's which codes to book procedures under so they make more money from insurance. His company is make 10s of million a year. There is stuff like that at every level.
And I might add that the inefficiency (in terms of national health outcomes vs. national public and private spending) is partially the reason, or explanation, that U.S. is the forefront of medical technology. The U.S. spends on things that develop technology but do not contribute much to national health.
Things like transplants, or cures for rare diseases, are generally not important for national health outcomes, but U.S. does a lot of work on these. You achieve low child mortality by forcing relatively simple things done for every child and family, even those who are not very receptive to care. U.S. does not do that as much as many other countries with lower spending but better national health outcomes.
