TUESDAY, March 15 (HealthDay News) -- Efforts to refer surgical patients to hospitals that handle a large number of such procedures did not improve patient outcomes, according to the results of a study in Washington state.

Previous research has suggested that surgical patients have better outcomes if they're referred to hospitals that perform a large number of operations. This has caused a push for volume-based referrals to hospitals, an idea led by the Leapfrog Group's Evidence-Based Hospital Referral (EBHR) program in the United States, the researchers explained.

However, the new study, which looked at what happened when a greater percentage of pancreatic and esophageal surgeries were performed at higher-volume hospitals, found that the impact on patient outcomes across the state was minimal.

Although rates of adverse events were lower at hospitals that met a given high-volume standard, rates of complications, death and hospital readmission did not improve in the seven years after the introduction of the EBHR program.

The study was published in the February issue of the Journal of the American College of Surgeons.

"This statewide analysis suggests Leapfrog's EBHR initiative has not had the intended impact of lowering the rate of adverse outcomes for all surgical patients having higher-risk surgical procedures. Although there are many potential reasons for this finding, it may be the result of higher-risk surgical patients not seeking care at higher-volume centers," lead author Dr. Nader N. Massarweh, a surgical resident at the University of Washington School of Medicine in Seattle, said in a journal news release.

More information

The U.S. Agency for Healthcare Research and Quality has more about surgery.