A new study finds physicians who use an e-prescribing system with formulary decision support can boost drug cost savings.

The report was funded by the Department of Health and Human Services' Agency for Healthcare Research and Quality.

According to the study, physicians can save $845,000 per 100,000 patients per year and possibly more system-wide by using a system that allows them to select lower cost or generic medications.

Complete use of an e-prescribing system with formulary decision support could reduce prescription drug spending by up to $3.9 million per 100,000 patients per year, authors found.

Many insurers use lists of approved prescription drugs known as formularies. Under these arrangements patients are often charged the lowest co-payment for generic medications .

A challenge to physicians' use of the tiered system is the lack of current data on insurers' prescription drug formularies because it changes frequently.

Researchers at Brigham and Women's Hospital and Massachusetts General Hospital in Boston examined data collected over 18 months from two major Massachusetts health insurers.

Physicians using e-prescribing with formulary decision support increased their use of generic prescriptions by 3.3 percent, the study's authors found.

Many doctors "want to do the right thing," said study author Joel Weissman of MGH. "If they are provided information on choices of effective medicines at the point of service, they are more likely to prescribe the one that will help their patients deal with the high cost of drugs."

The study's lead author, Michael A. Fischer, MD, of BWH, noted even physicians with e-prescribing use it only about 20 percent of the time. "Our results likely represent a conservative estimate of the potential savings," he said.

"These findings show that decision support can improve value for patients," said AHRQ Director Carolyn M. Clancy, MD.