HealthDay News -- In their final debate before the Nov. 4 election, John McCain and Barack Obama told the nation they intend to adhere to their respective plans for controlling costs and expanding access to health care, despite an ailing economy.

Democratic candidate Obama also put the Medicare Advantage plans on notice that he would consider cutting the subsidies they receive above-and-beyond traditional Medicare: some $15 billion a year, by his estimate.

But some observers question whether either candidate can realistically expand access and control costs.

"The problem is that its not clear whether either of their plans will do anything about the increasing costs both in terms of the Medicare Trust Fund and health-care costs in general," said Dr. Richard Kravitz, professor of medicine and director of the Center for Health Services Research in Primary Care at University of California, Davis Health System in Sacramento, Calif.

While both candidates talk about investing in prevention, very few preventive interventions save money, at least in the short term, Kravitz explained. "Many of these interventions are cost-effective, that is, you get good value for money, but you dont actually save dollars," he said.

And while both plans would expand coverage, neither would lead to universal coverage, he noted.

Moderator Bob Schieffer of CBS News kicked off the heath portion of the Oct. 15 debate by asking the candidates whether, given the current economic situation, either would now favor controlling health care costs over expanding health care coverage.

Republican candidate McCain reiterated his plan to give families a $5,000 tax credit to purchase the health insurance plan of their choice, saying "this will give them affordability; this will give them availability." He also highlighted the need to put medical records online and to expand community health centers.

To help Americans who dont have access to health insurance, Obama has proposed giving people the option of enrolling in a plan much like those offered under the Federal Employee Health Benefits Program. He would also expand eligibility for Medicaid and the State Childrens Health Insurance Program. Obama insists his plan would cut the average familys premium by $2,500.

"The truth is both are talking about improvements in the delivery of medical care," noted Robert Moffitt, director of the Center for Health Policy Studies at The Heritage Foundation in Washington, D.C. In each case, though, there is "maddening vagueness" about what exactly each administration would do and spend and how these changes would affect the way doctors, hospitals and other medical professionals, he said.

For example, both McCain and Obama back "pay for performance" for doctors, yet neither has described how they would implement it. "I cannot imagine anything more counterproductive to innovation in healthcare delivery or disruptive of the traditional doctor-patient relationship than government interference into the delivery of medical care, but thats what pay for performance actually would do," Moffitt said.

Despite similarities on the health delivery side, the candidates' philosophies about whether healthcare coverage should be mandatory provide a clear line of delineation. In the previous debate moderated by Tom Brokaw of NBC, McCain described healthcare as a "responsibility" while Obama said "it should be a right" for every American.

To learn more about each candidate's respective plan, go to www.acponline.org/advocacy/where_we_stand/election/.