are apparently Russia, Turkmenistan, China, and the USA. You can read all about it here. As the site says:
The United States has the rare distinction of being both one of the world’s richest countries and having one of its least-functional health care systems.Americans spend around one in every six dollars on healthcare. But, in aggregate, they’re not getting much bang for their buck. People in the United States are as likely to die from diseases like lung cancer as citizens in all OECD countries – which, on average, spend less than half as much per capita.
Looks like reform is in order.