Informal Physician Ties Forge Stealth ‘Networks’

The age of health reform places increased emphasis on pro­viders, and it might behoove insurers to find the informal ways that some physicians are connected. Often doctors have “a history of working with each other, and likely have evolved natural communication channels,” says “Variation in Patient-Sharing Networks of Physicians Across the United States,” which was published in the July 18 edition of the Journal of the American Medical Association.

One of the things the study looks at is how best to form accountable care organizations (ACOs), a bulwark of health reform. “Insurers and policymakers who want to influence physician behavior might find it more efficient to identify candidate accountable care organizations in this fashion.”

The study adds, “These informal information-sharing networks of physicians differ from formal organizational structures (such as a physician group associated with a health plan, hospital, or independent practice association) in that they do not necessarily conform to the boundaries established by formal structures. Informal information-sharing networks among physicians may be seen as organic or natural rather than as artificial or deliberate.”

That’s not to say that formal organizations do not influence relationships among physicians. They clearly do. “Formal networks are important, as evidenced by the unsurprising finding that physicians associated with the same hospital are far more likely than other physicians to be connected. Yet this is not always the case.”

For instance, although hospital affiliation appears to be the reason physicians connect in Albuquerque, that’s not the case in Minneapolis/St. Paul.

The study looks at administrative data for nearly 4.6 million Medicare beneficiaries in 2006. The patients were seen by about 68,000 doctors in 51 urban and rural hospital referral regions (HRRs). The number of physicians per HRR ranged from 135 in Minot, N.D., to 8,197 in Boston. “There was substantial variation in network characteristics across HRRs,” the study notes, adding that connected physicians had “more similar patient panels in terms of the race or illness burden than unconnected physicians.”

The study adds that “physicians tend to share patients with colleagues who have similar personal traits, practice styles, and patient panels, although the influence of some of these traits is small in magnitude.”