HealthDay News -- "Comparative effectiveness" is quickly becoming the latest catch phrase in health care.

A growing number of policy experts and medical groups clamber for data comparing one clinical intervention against other therapies for a given condition.

Advocates believe an expansion of comparative effectiveness research and greater coordination of these studies is the best way to squeeze more value out of the healthcare dollar while assuring optimal patient outcomes.

Comparative effectiveness "is going to be a very important part of helping us all make good decisions and 'buy smart' to improve the return on investments that we get from healthcare," said Dr. Carolyn Clancy, director of the Agency for Healthcare Research and Quality -- a division of the U.S. Department of Health and Human Services -- which conducts studies of clinical interventions by disease or condition.

President-elect Obama has already embraced the idea. His health reform platform called for the creation of an institute to "guide reviews and research on comparative effectiveness research," while Senate Finance Committee Chairman Max Baucus (D-Mont.) last year co-sponsored a bill to establish such an institute.

Both the Medicare Payment Advisory Commission and the Institute of Medicine have endorsed the concept, says the Alliance for Health Reform in an August 2008 report on the subject. In addition, medical groups such as the American College of Physicians (ACP) and the American Medical Association have called for the creation of a national entity to develop comparative effectiveness information.

It's not clear, however, how such an organization would be structured or governed.

"When you say something is going to be independent, you need some mechanism to have a committee or a board or a panel of some sort oversee the entire center, and the makeup of that independent board is really the X factor here," said Dr. Mark Helfand, director of the Oregon Evidence-Based Practice Center and professor of medicine at Oregon Health & Science University and the Portland Veterans Affairs Medical Center.

There is also dissention over whether the same organization should weigh in on the cost side of the equation. While ACP recommends that the same organization consider both comparative effectiveness and cost effectiveness, economist Gail Wilensky, a senior fellow at Project HOPE, argues that these functions should be kept separate.

Payers should do these analyses, not a national entity, because the use of cost-effectiveness data is "more politically contentious and its modeling is more technically controversial than comparative clinical effectiveness," she writes in the Annals of Internal Medicine.

Critics worry that a government-sponsored comparative effectiveness organization would ration care by limiting access to newer and pricier treatments. They point to Britain's National Institute for Health and Clinical Excellence, which recently denied access to four new kidney cancer drugs.

How a U.S.-based comparative effectiveness organization would prioritize its work is also an open question.

"If you have this centralized organization and everyone's looking to them for the answers, they can only do so much," said Amy Lischko, an assistant professor of public health and family medicine at Tufts University School of Medicine in Boston. "So what will they choose to do and how quickly will they be able to evaluate the new technologies?"

Regardless of how the movement evolves, comparative effectiveness data will put physicians in a position of power. "We can work to improve the quality of evidence simply by raising our standards for what kind of evidence is behind what we want to do," Helfand said.