American medical care may be the most expensive in the world, but that does not mean it is worth every penny. A study to be released Thursday highlights the stark contrast between what the United States spends on its health system and the quality of care it delivers, especially when compared with many other industrialized nations.

The report, the second national scorecard from this influential health policy research group, shows that the United States spends more than twice as much on each person for health care as most other industrialized countries. But it has fallen to last place among those countries in preventing deaths through use of timely and effective medical care, according to the report by the Commonwealth Fund, a nonprofit research group in New York.

Access to care in the United States has worsened since the fund’s first report card in 2006 as more people  some 75 million  are believed to lack adequate health insurance or are uninsured altogether. And within the nation, the report found, the cost and quality of care vary drastically.

The findings are likely to provide supporting evidence for the political notion that the nation’s health care system needs to be fixed. Both presumptive presidential nominees, Senator John McCain and Senator Barack Obama, argue that the country needs to get more value for its health care money, even if they do not agree on what changes would be most effective. But few people these days defend the status quo.