No one disagrees that one way to control ever-spiraling health-care costs is to manage diabetes better.

Yet when Vernice Davis Anthony, president and chief executive officer of the Greater Detroit Area Health Council, gathered a bunch of doctors in a room, they couldn't figure out the best way to do it.

Should they monitor blood sugars? What test would be the most effective? How about looking at eye disease? How about hypertension?

That debate lies at the heart of issues covered in the Advancing Value-Driven Health Care Incentives and Rewards Symposium, held yesterday and continuing today at the Philadelphia Marriott in Center City.

Sponsored by the National Business Coalition on Health, the conference focuses on the role of employers, which are the largest purchasers of health care through their employee-benefit plans. As big customers, companies have the most clout to change a health-care system that is expensive and often fails to deliver top-notch care.

"Value-driven health care," the organizers told the 260 attendees, means research into the best practices, rewarding providers and consumers for following them, providing transparent information about quality and cost, and linking it all through electronic data sharing.

The principles are lofty, the practicalities harder to attain.

Practicality mattered in Detroit, where Anthony found herself last year in the middle of the diabetes debate. The grand idea was to save $500 million in health-care costs over three years for 4.5 million people, partly by controlling diabetes. The question was how.

Michigan's largest employers - "the Autos" as she called them - "have been crumbling, and health care is a problem," she said.

General Motors Corp., for example, paid $4.6 billion for health care in 2006, covering 1.1 million employees, retirees and their families. Meanwhile, one GM person a day was dying a preventable death from a medical error, said Bruce Bradley, director of health-care strategy and public policy for General Motors.

Bradley now leads the council's Save Lives Save Dollars group to lower costs and improve quality. The group includes 70 percent of Detroit's largest employers and most of the area's hospitals and doctors.

Bradley's group focused on choosing attainable goals over less accessible ones. Key to picking those goals was finding something that could easily be measured using an accepted standard.

The insurers had to promise to reward hospitals and doctors who provided care according to the standard. In addition, the insurers had to agree to share best-practice information derived from claims data.

"That was the heavy, heavy lifting," Anthony said. When the insurers balked, the "Autos" applied pressure. "They said, 'You will participate if you want our business.' "

It was not hard to pick diabetes as one focus. More problematic was figuring out which performance measure should be the basis for rewarding health-care providers. Ultimately, the doctors settled on tracking blood pressure, mostly because it was practical.

Anthony said that it was too early to know the results, but initial reports were encouraging.

Having the leadership from the automakers was key, she said - a point the symposium's keynote speaker, Gov. Rendell, echoed in his presentation.

Employers "can do a lot by digging in your heels," Rendell said. "Just say no" to poor-quality care and mistakes, he said, and when the bills come, "don't pay them."

If something is not done to control costs and improve quality, he said, "no company will be able to offer health care, and if they do, the cost to employees will be so high that no employee will be able to afford it."

Contact staff writer Jane M. Von Bergen at 215-854-2769 or jvonbergen@phillynews.com.