http://www.oecd.org/document/16/0,2340,en_2649_34631_2085200_1_1_1_1,00.htmlIn 2004, the last full year given, the US spent 15.3% of its GDP on healthcare, the UK 8.1% - or $6102 and $2508 at Purchasing Power Parity exchange rates. The amounts that were public spending were 44.7% and 86.3% respectively - so that's $2728 and $2164. So the US spends more per person on Medicare, Medicaid, Veteran's Administration care and any other government programmes that I don't know about than the UK does for a programme that covers its entire population.
If you have money, and can afford the care, it's probably better in the US. The UK has made some decisions not to provide some expensive drugs via the NHS - and getting them via private insurance might not be easy either (like most people in the UK, I don't have private insurance). It's undoubtedly true that some healthcare is rationed because of budgets in the UK - and while waiting lists have decreased in the past few years, we still have to wait weeks or months for things that many countries would schedule in days.
Here's a long article co-authored by Paul Krugman on healthcare spending.
Over the years since the failure of the Clinton health plan, a great deal of evidence has accumulated on the relative merits of private and public health insurance. As far as we have been able to ascertain, all of that evidence indicates that public insurance of the kind available in several European countries and others such as Taiwan achieves equal or better results at much lower cost. This conclusion applies to comparisons within the United States as well as across countries. For example, a study conducted by researchers at the Urban Institute found that
per capita spending for an adult Medicaid beneficiary in poor health would rise from $9,615 to $14,785 if the person were insured privately and received services consistent with private utilization levels and private provider payment rates.<4>
The cost advantage of public health insurance appears to arise from two main sources. The first is lower administrative costs. Private insurers spend large sums fighting adverse selection, trying to identify and screen out high-cost customers. Systems such as Medicare, which covers every American sixty-five or older, or the Canadian single-payer system, which covers everyone, avoid these costs. In 2003 Medicare spent less than 2 percent of its resources on administration, while private insurance companies spent more than 13 percent.
At the same time, the fragmentation of a system that relies largely on private insurance leads both to administrative complexity because of differences in coverage among individuals and to what is, in effect, a zero-sum struggle between different players in the system, each trying to stick others with the bill. Many estimates suggest that the paperwork imposed on health care providers by the fragmentation of the US system costs several times as much as the direct costs borne by the insurers.