If your aging parents are thinking of moving to Florida, you might want to suggest Fort Myers, not Miami-Fort Lauderdale. They'll live just as long there, but the healthcare will be less intense and less expensive. And when they die, they'll be less likely to do so in what one researcher calls ''a therapeutic frenzy,'' hooked up to tubes and machines.

That's one of the conclusions in a new study by Dartmouth Atlas, an organization whose analyses showing widely divergent healthcare costs around the United States have for years shaped the healthcare debate.

Previous Dartmouth studies have revealed South Florida's healthcare to be among the nation's most costly, and that trend continues.

In Miami-Dade and Broward counties, 16 hospitals rank among the top 5 percent in the country in healthcare costs for patients in their last two years of life. All 33 are in the top 20 percent.

Peter Orszag, director of the Congressional Budget Office, said the Dartmouth research has ``unbelievable value.''

Orszag told a Senate committee that by reducing expenses in high-cost areas like South Florida could result in as much as $600 billion in savings on a national basis.

Dartmouth studies indicate that can be done without reducing quality of care.

In fact, the latest study says, the more money spent and the more care provided, the higher the risk of dying: ``Your chances of dying increase in regions where the healthcare system delivers more care.''

EXCESSIVE PROCEDURES

The reason is that some people ''will be harmed'' by having too many procedures done, said Elliott Fisher, the Dartmouth report's co-author. ''On average, there is no survival benefit'' from more aggressive care.

Dartmouth's data can be read as a blueprint for building a better, cheaper healthcare system that can cover more people, Fisher believes.

''There are huge opportunities to improve the efficiency of care,'' he said.

South Florida healthcare providers had better get more efficient, or they risk Congress stepping in and lowering Medicare reimbursements, warns Becky Cherney, president of the Florida Health Care Coalition, an organization of major corporations dedicated to improving quality and lowering cost of care.

''It's really time for the South Florida medical community to react,'' she said.

Dartmouth researchers believe the way to do that is by getting doctors to focus on what's called evidence-based care, following proven treatments -- for example, always give an aspirin to a heart attack patient -- rather than ordering multiple tests to see what they find.

The problem is that, at present, the system rewards providers each time more care is ordered, but not for being efficient, says Fisher.

The result is that there are wide discrepancies even within the expensive South Florida region. Among the Dartmouth report's findings:

• In Broward and Miami-Dade counties, Mount Sinai in Miami Beach ranks near the top for the amount of care. For the last two years of life, its average patient will cost Medicare $52,650 for in-patient services. In the patient's last six months, she will spend 25 days in the hospital and be subjected to 74 doctor visits. That's far more than the $28,148 spent at Imperial Point in North Broward, where the patient will spend 14 days in the hospital and have 48 doctor visits.

• In Miami, patients associated with Pan American Hospital (now Metropolitan Hospital) are the most likely to die in the hospital -- 50 percent. That's more than double the 23 percent rate at Florida Medical Center in Lauderdale Lakes.