The care that patients receive for a given condition depends more on their geography than on the condition itself, according to the latest reports from the Dartmouth Atlas Project. The reports documented wide variations in eight elective procedures performed on Medicare beneficiaries in nine regions of the U.S.

During a teleconference with reporters, Shannon Brownlee, author of the book Overtreated: Why Too Much Medicine is Making Us Sicker and Poorer, referred to these operations as "preference-sensitive" procedures, because they reflect conditions for which multiple treatment options exist.

Brownlee, lead author of the reports, cited the example of early-stage breast cancer and the fact that the two main treatment options—a lumpectomy or a mastectomy—had tradeoffs. Researchers found that women older than 65 in Grand Forks, N.D., were seven times more likely to have a mastectomy for early-stage cancer than women in San Francisco.

The other procedures highlighted in the report, which used Medicare data from 2008 to 2010, were coronary artery bypass surgery, percutaneous coronary intervention, back surgery, knee replacement, hip replacement, carotid endarterectomy, cholecystectomy, transurethral resection of the prostate, prostate cancer screening and radical prostatectomy for prostate cancer.

"If you have heart disease and live in Reno, Nev., you are half as likely to undergo balloon angioplasty than if you live in Las Vegas, and twice as likely to undergo back surgery than if you live in Roswell, N.M.," the introduction to the Mountain State report (PDF) stated. "If you have osteoarthritis of the knee and live in Bountiful, Utah, you are nearly three times more likely to have your knee replaced than if you live in Santa Fe."

Dr. David Goodman, co-author of the report and co-principal investigator for the Lebanon, N.H.-based Dartmouth Atlas Project, referred to these regional variations as a distinctive "surgical signature." He also said that the signature develops from local training programs, and it often is invisible to patients and physicians.

"Geography is too often a destiny in healthcare," Goodman said during the teleconference. Noting that patients often prefer less-intensive treatments, Goodman said the solution lies in true "shared decision-making" in which patients are educated on expected outcomes with each option being considered and in which their preferences play a major role in their choice of treatments. Although more information is available to patients than ever before, Goodman said this is having "remarkably little" impact on whether patient preference is followed.

In October, the Dartmouth Atlas Project released a report documenting variations in styles of care at the country's teaching hospitals and suggesting that medical students take these patterns into account when choosing a residency program.