More intensive medical care -- even at some of the most reputable hospitals in the nation -- does not necessarily translate into longer life or better health and may in fact leave patients worse off, according to research released yesterday.

Elderly patients with chronic illnesses who stay in the intensive care unit longer, receive more diagnostic tests or are treated by numerous specialists do not fare better than those who receive less intensive care, two studies conducted by Dartmouth Medical School found.

"We know hospitals are dangerous places," said Elliott Fisher, one of the lead authors and co-director of the Veterans Affairs Outcomes Group based in Vermont. "Higher intensity patterns of practice are associated with no better quality and, if anything, worse quality."

Among older patients who were treated for a heart attack or colorectal cancer, there actually "was a small but statistically significant increase in the risk of death as intensity increased," he found.

"It is clear that quality is inversely correlated with the intensity of care and that the better hospitals are using fewer resources and providing fewer hospitalizations and physician visits," said co-author John E. Wennberg, director of Dartmouth's Center for Evaluative Clinical Sciences.

The pair of studies, published in the journal Health Affairs, lend support to a growing movement in health policy circles toward "evidence based medicine" in which doctors adhere to scientifically proven treatments and providers are paid for results rather than procedures.

Insurers and Bush administration officials said they hope to use the data to demand lower-cost care with proven success rates.

"Higher costs don't necessarily mean higher quality," said Mark McClellan, administrator of the federal Centers for Medicare and Medicaid Services, which sets policy for the programs. "We see great opportunities to improve health without spending more money."

Many in the medical profession, however, cautioned that quality measures are subjective, patient preferences influence treatment decisions and the debate over medical spending cannot ignore prices and profits.

The reason the United States spends more on medical care is "not because Americans use so much more health care, but because our prices are higher and because our decentralized, pluralistic system generates extraordinary overhead costs," wrote former Medicare chief Bruce Vladeck in an accompanying article. "Focusing on utilization permits both providers and payers to change the subject away from the more embarrassing discussion of who's getting paid, by whom and how much."

For three decades, researchers at Dartmouth have tracked wide geographic variations in treatment patterns across the country, focusing primarily on the underuse of types of care proven to be effective. More recently, the team shifted its attention to potential overuse of care. The reports published yesterday are the first to analyze treatment patterns at specific hospitals.

In the first report, Wennberg examined the Medicare records of 90,600 patients during the last six months of life in 77 well-regarded teaching hospitals. He compared frequency of doctor visits and hospitalizations and time in the intensive care unit for people with solid tumor cancers, congestive heart failure and chronic lung disease.

He found dramatic variations in the amount of care given to patients with the same maladies. Patients at New York's Mount Sinai Medical Center, for instance, spent almost twice as many days in the hospital as those in the Mayo Clinic's St. Marys Hospital in Rochester, Minn.

The number of terminally ill patients who died in the hospital, rather than at home or in hospice, ranged from 32 percent to 52 percent, despite surveys that indicate most Americans prefer not to die in a hospital.

"If you can get the same benefits for patients with lower intensity use, then you have a more efficient system in which to provide that care" said Ralph Horwitz, dean of Case Western Reserve University School of Medicine in Cleveland. He said the studies were valuable, because for too long "we have substituted volume for a measure of quality."

Yet practicing physicians are often frustrated by attempts to measure quality because they overlook what doctors "take the most pride in: to make countless daily decisions about diagnosis and treatment using copious, incomplete, confusing and changing information, under time pressure and in the face of an ambiguous medical literature," wrote Harvard Medical School professor David Blumenthal.

Fisher's analysis tracked mortality rates for Medicare patients in 300 hospitals for heart attacks, colorectal cancer or hip fractures. After devising five categories based on "intensity" of care, he found that "high-intensity" institutions spent vastly more money -- on X-rays, specialist visits, inpatient care and follow-up -- than the "low-intensity" hospitals. But the high-end hospitals are "not doing a better job on quality," he said.

Robert Dickler, senior vice president of health care affairs at the Association of American Medical Colleges, said the reasons for variations may vary, noting that some hospitals may keep patients longer simply because there is no bed available at a skilled nursing home. Still, he expects teaching hospitals to use the reports to improve care and efficiency.

The Health Affairs issue was underwritten by the WellPoint Foundation, a charitable arm of the California-based health insurer. Chief executive Leonard Schaeffer said the articles should serve as a wake-up call.

"In the current system, poor quality pays," he said. "Physicians are reimbursed for both incorrect treatment and effective therapy."