Seniors living in areas with more primary care have slightly lower death rates and are less likely to end up in the hospital with a preventable disease, U.S. researchers have found.

In contrast to some earlier studies, which have yielded mixed results, the new work looked at how much primary care was actually delivered to patients - not just how many primary care physicians were in a certain area.

“The magic is not in how many primary care physicians there are, it is what they do,” said Dr. Barbara Starfield of the Primary Care Policy Center at Johns Hopkins University in Baltimore, who was not involved in the study.

Experts say primary care physicians - general internists and family doctors - are irreplaceable parts of the healthcare system, because they are easily available and can coordinate a broad range of health services.

The number of medical students who go into primary care has been dropping in recent years, fueling concerns over how this will impact the aging nation’s health.

“We just can’t hope to improve healthcare in this country unless we train primary care physicians right,” Starfield told Reuters Health.

The new report, published in the Journal of the American Medical Association, tapped into Medicare data, which includes patients 65 years and older. The authors included a sample of more than five million seniors.

First, they linked age-adjusted death rates, hospitalizations and Medicare spending to the number of primary care physicians across the U.S. based on headcounts from the American Medical Association (AMA).

Based on that those data, areas in the top one-fifth of primary care physicians saw tiny improvements in preventable diseases over those in the bottom one-fifth. But that didn’t extend to deaths.

However, when the team used a measure of how many doctors listed in the headcounts were actually practicing primary care, the differences became much larger.

Areas in the top one-fifth had 5.19 deaths per 100 Medicare beneficiaries annually compared to 5.49 per 100 for the bottom one-fifth, for instance.

For preventable hospitalizations due to diseases like asthma and diabetes, the rates were 73 per 1,000 beneficiaries and 79 per 1,000 respectively.

In theory, if all of the U.S. reached the highest level of primary care, that would translate into nearly 50,000 fewer deaths and about 436,000 fewer hospitalizations over a year, the researchers estimate.

Although the study did account for differences in how sick patients were in the different areas, as well as income and the number of specialist doctors, it doesn’t prove that the gap in outcomes is caused by differences in primary care.

“Areas with more primary care are more likely to have better outcomes but whether or not that is due to primary care, we don’t know,” said Chiang-Hua Chang, a researcher at the Dartmouth Institute for Health Policy and Clinical Practice in Lebanon, New Hampshire, who worked on the new study.

Things like better organization or coordination of care might also play a role, she told Reuters Health.

The researchers also found that areas with the highest levels of primary care spent $88 more per Medicare beneficiary - corresponding to nearly $14 billion nationwide, if the model’s assumptions are correct.

“A lot of people feel that primary care may save money” Chang said, “but my study does not support that.”

Starfield said more primary care in itself was unlikely to lead to extra spending.

“What generates cost in a healthcare system is specialists,” she said. “Ninety-nine percent of the evidence shows you need strong primary care to improve the healthcare system, otherwise the costs are going to run away.”

While the healthcare reform act has earmarked some money to overhaul the training of medical students and expand primary care services, Starfield said it is far from sufficient.

“We absolutely aren’t focusing enough on this,” she told Reuters Health.

SOURCE: Journal of the American Medical Association, online May 24, 2011.