A past president of the American Society of Transplant Surgeons has gone public with a question often posed by many of his colleagues in private: Why do some transplant centers only report survival data for a relatively low percentage of their patients?

This survival data, collected by the United Network on Organ Sharing (UNOS), which operates the nation's transplant network, is made public each year to aid the 75,000 Americans waiting for organ transplants in making choices among the nation's 270 transplant centers.

Presumably, if every center reported survival data for virtually all of its transplant patients (a small number of patients move without providing new contact information), patients awaiting transplants would be able to make comparative judgments about success rates.

A person needing a kidney transplant in Florida, for example, might be interested in the fact 95.1 percent of those who had such a transplant at the University of Miami Transplant Center still had their new kidney functioning at the end of one year, compared to 89.2 percent at Florida Hospital Medical Center in Orlando.

As it happens, both the University of Miami and Florida Hospital Medical Center reported survival data for 99 percent of their kidney transplant patients, facilitating a valid comparison.

But what about the person needing a kidney transplant in Chicago, who tries to compare the one-year kidney survival rate of 87.9 percent at Rush Presbyterian St. Luke's Medical Center to the 86.2 percent reported by the University of Illinois in Chicago.

On the surface, it would appear that the rates are not very different. But while Rush Presbyterian reported data for more than 99 percent of its transplant patients, the University of Illinois reported data for only 52 percent.

Hence, the question for anyone considering the University of Illinois: If it had reported data for virtually all of its patients, would the kidney survival rate for its patients be better -- or worse?

Until now, no one has spoken out publicly about this problem. But Dr. Hans Sollinger, director of the transplant program at the University of Wisconsin, one of the nation's largest, publicly complained about the incomplete reporting in an interview with the Milwaukee Journal Sentinal.

"I'm going to write an article to one of the medical journals about the accuracy of reporting," Sollinger said. " Reporting requirements have to be uniformly enforced across the country. The centers are not complying and perhaps there should be some penalty."

The University Renal Research and Education Association (URREA), which now has the federal contract for publishing the data collected by UNOS, said that "we of course are concerned" about centers providing only partial information.

"But we are not the policeman," said URREA President Philip Held.