WEDNESDAY, Jan. 28 (HealthDay News) -- Hospitals that perform at least 20 lung transplants a year have the lowest death rates for this complex procedure, according to Johns Hopkins researchers.

They said their findings could serve as a patient safety benchmark or standard for hospitals nationwide.

The researchers analyzed data from the 79 American and Canadian medical centers that perform lung transplants. At the roughly 20 institutions that perform, on average, 20 or more lung transplants a year, the chances of an organ recipient surviving the critical first month after transplant are more than 95 percent, and the chances of surviving the first year are 83 percent. The rates in hospitals that perform two or fewer lung transplants per year are 90 percent and 73 percent, respectively.

The findings were expected o be presented this week at the annual meeting of The Society of Thoracic Surgeons in San Francisco.

"Lung transplantation is an incredibly complex procedure, and our results show that the so-called 'center-effect' is a very real phenomenon. Hospitals that do more, do them better," study senior investigator and transplant surgeon Dr. Ashish Shah, said in a Hopkins news release.

"For best patient outcomes, you need the right staff operating at peak skill level, with patient support systems ingrained in both their clinical operations and their organization's culture," said Shah, an associate professor at the Johns Hopkins University School of Medicine and its Heart and Vascular Institute.

"Our findings do not mean that only high-volume centers should perform lung transplantation," lead investigator Dr. Eric Weiss, a postdoctoral research fellow in cardiac surgery, said in the news release. "But it does mean that patients should consider consistently high volumes when evaluating their choices of where to have their transplant done, and it does mean that lower-volume centers really do need to learn from the higher-volume hospitals, taking a careful look at what they are doing right to raise their survival rates and lower a recipient's chances of dying or suffering complications from surgery."

"Our hope is that this evidence will be useful in establishing budgets and staffing objectives so that low-volume centers, too, can steadily improve their patient outcomes in lung transplantation," Shah said.

In 2007, more than 1,400 lung transplants were performed in the United States. Thirty-nine percent of those patients have survived for at least a year, and 6 percent died within a month of surgery. About 2,000 Americans are on lung transplant waiting lists, and 90 others are waiting for both a heart and a lung.