PITTSBURGH, January 9, 1998 — An analysis of survival rates at U.S. liver transplant centers identifies 11 centers of excellence and confirms previous studies that show survival rates are significantly better at centers that do a large volume of liver transplants per year. But because of growth in the transplant industry, with more centers doing small numbers of transplants, patients, as consumers, have to become more educated to assure they choose a high quality center, says a policy research consultant for the University of Pittsburgh, which has argued for more government oversight of the transplant system.
CONSAD Research Corporation performed the statistical analysis for the University of Pittsburgh Medical Center (UPMC). CONSAD researchers used data from a report the federal government released last month that provides patient and graft survival rates at the 103 U.S. liver transplant centers in operation between Jan. 1, 1988 and April 30, 1994. (There are now 122 liver centers.) The report was published by the Department of Health and Human Services (HHS) for its contractor, the United Network for Organ Sharing (UNOS), which operates the national system. Liver transplant programs were evaluated in relation to their risk-adjusted expected survival rates. UNOS found 24 percent of the liver transplant programs fell below their expected marks and 11 percent of the programs achieved higher than expected rates. The remainder were judged to be performing at their expected levels.
"Our analysis shows very convincingly that there is a strong relationship between a center’s success rate and the volume of transplants it annually performs," said Fred Rueter, Ph.D., vice president at CONSAD. "UNOS conducted a similar study in 1994 after its release of center-specific survival rates and reached the same conclusion then. The centers that do better tend to be ones that do many transplants; the centers that do worse tend to be low-volume centers."
According to Dr. Rueter, the best measures of a center’s quality are its three-month survival rates, which reflect the center’s surgical proficiency, and its one-year survival rates, which indicate the center’s ability to manage episodes of rejection and infection that are common in the first year. CONSAD examined all of the centers’ three-month and one-year patient and graft survival rates in its analysis.
Eleven centers emerged that had rates significantly higher than expected on at least two of these measures. The centers were: the UPMC; Baylor University Medical Center in Dallas; University of California, San Francisco and California Pacific Medical Center in San Francisco (which have now merged); Rochester Methodist Hospital (Mayo Clinic) in Rochester, Minn.; Cedars-Sinai Medical Center in Los Angeles; the University of Alabama Hospital in Birmingham; University of Wisconsin Hospital and Clinics in Madison; St. Christopher’s Hospital of Children in Philadelphia; University of Nebraska Medical Center in Omaha; and New York University Medical Center.
Of these 11 centers, seven performed, on average, more than 50 transplants per year, with the UPMC having the highest average annual volume at 360.
There were more than twice as many centers that had survival rates significantly below what would be expected of their programs on two or more measures. Of these 27 centers, 22 were programs that performed an average of 25 or fewer transplants each year.
Two thirds, or 72, of the 103 liver transplant programs included in the recent UNOS report performed fewer than 25 transplants a year. The CONSAD analysis showed these centers had average one-year patient survival rates 10.2 percentage points lower than would be expected. The same analysis found that the 13 centers that performed more than 50 transplants a year had average one-year survival rates 2.4 percent higher than expected, this despite the fact that larger centers tend to attract patients with more medical complications.
"Patients would be wise to carefully evaluate the data in the UNOS Center-Specific Report. While it shows survival rates and center volume are two very important parameters to consider, patients should also ask about a center’s average wait on the list, its willingness to accept patients with various risk factors, and the center’s track record for turning down suitable organs for nonmedical reasons," cautions John Fung, M.D., Ph.D., associate professor of surgery and chief of the division of transplantation at the University of Pittsburgh Thomas E. Starzl Transplantation Institute .
Dr. Fung has been critical of the current liver allocation system, which has resulted in disparate waiting times across the country and unnecessary waiting list deaths. The lack of government oversight has also allowed a proliferation of transplant centers, many with high mortality rates.
For some time, HHS has been expected to issue final regulations governing the national transplant system. Following the release last month of transplant centers’ survival rates, HHS asked UNOS to report back within 30 days following a review of 29 transplant programs, including nine liver programs, that had worse-than-expected survival rates.