Volume is good, but excellence is better.
That is one of the conclusions drawn from the 63-page public report on a California program in which hospitals voluntarily reported their outcomes for coronary artery bypass graft surgery.
The report, based on risk-adjusted data from 2000 to 2003, concluded that on balance, higher-volume providers had better outcomes, but though the finding was statistically significant, "The volume-outcome relationship was not extremely strong."
Still, the report concludes, if 25,000 patients undergoing so-called "isolated" CABG procedures were sent to the hospitals that had an annual volume of at least 250 CABG cases per year, 50 lives would be saved. If the patients were sent to hospitals doing 450 or more isolated CABGs per year, 110 lives would be saved.
In 2002, the median number of CABG-only procedures performed in the 77 participating hospitals was 172. The high was 1,051 and the low was 9.
"Certainly, high volume is not a guarantee of good performance," said Joseph Parker, director of the healthcare outcomes center at the Office of Statewide Health Planning and Development, the California agency that has run the program since 1997. The voluntary program will be supplanted later this year by a mandatory reporting program under a state law passed in 2003.
The first report of mandatory results for all California hospitals with heart programs (there were 121 in 2002) is due to be released by Parker's office this fall using data from 2003. A follow-up report will cover data from 2003 and 2004 and will be released in fall 2006. It will include reports on both hospitals and individual surgeons.
Four other states, Massachusetts, New Jersey, New York and Pennsylvania have similar CABG reporting programs, Parker said.
Eight of the participating hospitals performed "significantly better than expected," given their anticipated mortality rates and actual outcomes. The report showed a wide variation in preoperative death rates, from 1.6% to 5.3%, which "underscores the importance of adjusting for differences in case mix." It also noted a "close agreement" between the actual and the predicted number of deaths using the given risk-adjustment model.
"Consequently, hospitals and surgeons should not exclude high-risk patients from appropriate CABG surgeries as a means to improve performance scores."
Parker said the state uses the same data-gathering methodology that the Society of Thoracic Surgeons uses in its national surgical database for reporting to members, but tweaks the risk-adjustment model somewhat. How the individual surgeons' performance will be depicted in the upcoming public report has not yet been determined, but Parker said they most likely will be assigned the labels "as expected," "better than expected," or "worse that expected."
The state needs to improve on the dense, data-laden document issued Monday, he said, noting "Our reports are not as consumer friendly or as consumer focused as we'd like them to be."
Parker said he is concerned that physicians won't trust the risk-adjustment mechanism and shun more complicated cases out of fear an increased number of negative outcomes will skew their personal ratings.
"It's clearly something we are very worried about."
Cardiac surgeon Vincent Gaudiani, M.D., said Parker has good reason for concern.
Gaudiani says he performs about 300 heart procedures a year at Sequoia Hospital in Redwood City. He and his partner account for the entire CABG volume at the hospital. Gaudiani also said he's posted his results online for seven years, so the state mandated disclosure holds no fear for him. But for other physicians, he's not so sure.
"The risk adjustment I think is fair," Gaudiani said. "But the problem, in a highly scrutinized business, when you lose a person's life, you are a chump.
"It has a psychological effect of saying, 'Why should I do this? This is a very high-risk patient who is probably going to die. Why should I take the risk?"
"Cardiac surgeons already feel this pressure," Gaudiani said. "In order to preserve the sense of who they are, they are going to become more conservative. This kind of scrutiny automatically imposes psychological burdens on the surgeon."
Gaudiani compared it to driving and looking in the mirror and seeing a highway patrol officer behind you.
"You feel differently and drive differently," he said.