Doctors Tend to Share Patients With Similar Colleagues

FRIDAY, July 20 (HealthDay News) -- U.S. doctors tend to share patients with colleagues who have similar personal and practice styles, according to a new study.

The findings are from a Harvard Medical School study that looked at informal patient-sharing networks among doctors across the country. The researchers used 2006 data from nearly 4.6 million Medicare patients seen by more than 68,000 doctors in 51 urban and rural hospital referral regions.

The study was published in the July 18 issue of the Journal of the American Medical Association.

There was substantial variation between the doctors' informal sharing networks. The number of doctors included in a network ranged from 135 in Minot, N.D., to nearly 8,200 in Boston. The average number of other doctors each doctor was connected to per 100 Medicare patients was 27.3.

Doctors were far more likely to have connections with doctors based at the same hospital than those based at different hospitals. Connected doctors also were much more likely to be in close geographic proximity: The average distance for connected doctors was 13.1 miles, compared to 24 miles for unconnected doctors.

The researchers also found that patient characteristics such as race, age and health conditions were more similar among connected doctors than among unconnected doctors.

"It has long been known that physician behavior varies across geographic areas, yet our understanding of the factors that contribute to these geographic differences is incomplete," Dr. Bruce Landon, professor of health care policy at Harvard Medical School in Boston, said in a journal news release. "Our findings suggest that variation according to network attribute might help explain health-care variation across geographic areas, particularly given what is known about how networks function."

Strong connections among doctors -- as well as among doctors, nurses and administrators -- can create trust and shared values that improve health care for patients, Valerie Lewis and Dr. Elliott Fisher, both professors at Dartmouth University's Geisel School of Medicine in Hanover, N.H., wrote in an accompanying editorial.