Americans are increasingly turning to emergency departments and subspecialists rather than their personal physicians for acute care, a new study finds.

Researchers analyzed data on more than a billion outpatient visits made between 2001 and 2004. About a third of those visits were for acute care, including new health problems and flares of such chronic conditions as asthma and diabetes.

About 45 percent of the 354 million annual acute-care visits were made to primary care doctors, according to the study. Of those, 22 percent of patients were seen by general or family practitioners, 10 percent by general internists and 13 percent by pediatricians.

Some 28 percent went to emergency departments, 20 percent to non-primary care office-based subspecialists and 7 percent to hospital outpatient departments.

Dr. Arthur Kellermann, a senior principal investigator at the RAND Corporation in Arlington, Va., and a study co-author, said that to improve the nation's health-care system and health outcomes, the over-reliance on emergency departments and under-valuing of primary care doctors has to change.

"There is ample evidence that countries and states with strong vital primary care systems have better health outcomes and lower health-care costs," Kellermann said. "Having a doctor that manages your health, who can work with you in terms of making health-related decisions, is a benefit to you and the society."

The study's findings are published in the September issue of Health Affairs.

Certain provisions in the health-reform legislation enacted this year should address the situation somewhat, Kellermann said. They include increased funding for primary care and support for training additional primary care doctors and for establishing patient-centered medical homes, which emphasize collaboration and coordination of care and provide a framework for physicians to delegate more routine and administrative tasks and instead focus on the complex tasks only they can do.

The shift won't come a moment too soon. The new health legislation is expected to swell the numbers of insured Americans by 32 million, according to the study, many of whom will be seeking primary care.

To accommodate them, experts agree that access issues have to be addressed. Though less than 5 percent of the nation's doctors are emergency physicians, they handle more than 28 percent of all acute-care encounters, according to the study.

Many doctors express frustration that the endless grind of administrative tasks, along with back-to-back, 15-minute appointments, makes it difficult to take unscheduled visits or to spend the time they would like with a patient who needs to be seen for difficult-to-diagnosis, potentially serious problems.

"Doctors feel frustrated that they're not able to drop everything and give those patients their undivided attention for as long as it takes," Kellermann said. "You can't do that if the waiting room is piling up and everyone is getting angry."

An increasing elderly population, the growing burden of chronic disease and the time it takes to coordinate care across multiple physicians have added to the workload, he said.

Upper respiratory illness such as cough and sore throat, skin rash and earaches were among the top reasons that brought people to primary care doctors, the study found. Office-based specialists tended to handle acute-care visits for conditions in their areas of expertise. For example, dermatologists saw skin problems, ophthalmologists treated eye problems and so on. Acute-care visits to hospital emergency departments were typically for potentially dangerous conditions such as stomach and abdominal pain, chest pain and fever.

About 95 percent of acute-care visits to office-based primary care doctors and subspecialists occurred on weekdays. In contrast, 67 percent of acute-care visits to emergency departments took place on weekends or after hours.

Dr. Olveen Carrasquillo, chief of the Division of Internal Medicine at the University of Miami Miller School of Medicine and an internist and researcher at University of Miami Hospital and Clinics, said it's important for practices to offer some sort of after-hours or weekend care for patients to avoid over-use of emergency departments.

"Sometimes people need to talk to someone about what to do and what is going on," Carrasquillo said. "Without that, they jump at the next best thing, which is going to an emergency room."

Training more primary care doctors to address shortages and reforming payment schemes that under-value primary care is also critical, Carrasquillo said. "Without an adequate primary care workforce, just giving people an insurance card is not enough," he said.