Veteran health policy experts Thursday urged lawmakers to put aside ideological differences and take immediate action to create broad based changes in the nation’s health care system.

The group, which included leading economists, analysts and health care administrators, spoke at an event organized by the non-profit advocacy group Health Reform, USA. The event coincided with the group’s publication of an open letter (.pdf) to Congress, which was signed by more than 400 health care leaders and identified eight specific policy changes that the leaders said are central to effective health reform legislation. Those changes include efforts to expand coverage to the uninsured, promote competition in health insurance, assure affordability and cover preventive services.

Many of the panelists, who were involved in past failed health reform efforts, warned that the financial security of the middle class is in danger if Congress does not act.

Princeton economist Uwe Reinhardt, who was among the co-signers, noted in a statement that a typical privately insured American family now pays $16,700 for health care, which will double again by 2019 while wages and salaries rise at less than 3 percent per year. “Many middle-class Americans seem unaware that they are sailing into a perfect storm,” he said.

Overall, the group emphasized that the proposal unveiled yesterday by Senate Finance Committee Chairman Max Baucus, D-Mont., is a strong framework that moves toward the goal of meaningful health reform. Although the panelists questioned some specific provisions, especially the bill’s ability to expand affordable health coverage while also slowing the growth of cost increases, they advised lawmakers to fight the urge to walk away from the increasingly difficult legislative process.

Charles Kahn, president of the Federation of American Hospitals, said Baucus’ bill will face “pot shots” from the left and right. Still, he added, it puts the legislative process on the right track. “Good intentions just won’t do it,” Kahn said. “You can’t make an omelet without breaking the eggs.”

The group emphasized the need to stay open to compromise, to focus on the big picture and to think about how proposals will work in the real world.

For instance, Stuart Altman, a health policy professor at Brandeis University and a health advisor to Presidents Nixon and Clinton and to candidate Barack Obama, said he would have liked the proposal to provide subsidies for people earning more than 300 percent of the federal poverty level to purchase health insurance. The poverty level is $22,050 for a family of four. Still, he applauds the measure’s effort to cap out-of-pocket costs at 13 percent of income.

William Roper, chief executive of the UNC Health Care System at the University of North Carolina at Chapel Hill, stressed the need to look at the overall effect of reform instead of each small part. Some aspects of the overhaul proposals, he said, would likely cause his hospital to receive lower payments from the government for treating Medicare patients but the reform would simultaneously help with the crushing costs of paying for the uninsured.

“Things are not working in the real world,” Roper said. “It’s increasingly difficult to make that math work.”