There goes one popular assumption about high medical costs.

New research suggests reducing non-urgent visits to emergency departments—a growing focus of both private and public insurance plans—will yield little to no savings for the health care system. The research was published last week in Annals of Emergency Medicine.

"The focus on non-urgent ER visits distracts from the potential savings that do exist in the area of hospital admissions," says lead study author Dr. Peter Smulowitz, a doctor of Beth Israel Deaconess Medical Center in Boston. "Emergency department patients are responsible for about half of all hospital admissions, and those admissions account for about 15 percent of all health care expenses. Many patients are admitted to the hospital from the ER either because the gaps in the rest of the health care system leave patients without other good care options, or because a fragmented system has failed to care for their complex chronic disease."