Incentives for the Overprescription of PCI. The introduction of PCI to the cardiologists' armamentarium in the 1980s resulted in a fall in number of CABG operations performed.1 Presently, for most patterns of clinically significant CAD, stent-assisted PCI can be substituted for CABG, although controversy surrounds the long-term outcome of DES-assisted PCI.15 Because of this ability to substitute PCI for CABG, many cardiac surgeons have alleged that cardiologists are performing more PCI procedures and referring fewer patients for cardiac surgery.16 Cardiac surgeons have further opined that the cardiologists have (wrongfully) increased their own invasive treatment of CAD to compensate for a fall in their real income.17 Yet virtually nothing objective has been written to support this opinion.
Analysis of the relationship between the performance of PCI and CABG is complicated by the phenomenal market growth for cardiac services. In the current study, the total volume of cardiac services (PCI and CABG cases) performed in New York State increased 30% from 49,736 in 1997 to 64,739 in 2003. This growth rate, which is far in excess of the 1% to 2% population growth in New York State during this period, appears to be entirely due to growth in the PCI sector. During the 7 years of this study, not only did the number of PCI procedures performed increase by 75% but also the number of CABG operations fell by one-third.
Cardiologists, on the other hand, have attributed the growth of the PCI sector to the addition of stents to PCI procedures. In the view of cardiologists, stenting has made it possible for more patients with 2- and 3-vessel CAD to be treated with PCI rather than CABG operation. Yet the growth of the PCI sector cannot be entirely explained by cardiologists' self-referral patterns, for two reasons. First, hospitals give cardiologists incentives to refer patients to cardiac surgeons.18 Today, cardiologists are using more stents per patients than ever before19 to improve the long-term cost-effectiveness of stent-assisted PCI.20 Hospitals, however, are reimbursed per PCI procedure and not per number of stents used. The cardiologists' current stent/PCI utilization makes PCI a universal money-losing procedure for hospitals.2 The downward pressure that hospitals place on cardiologists not to overprescribe stent-assisted PCI is a likely reason that utilization studies from the United States21,22 and Europe23 have demonstrated that cardiologists are appropriately referring patients for PCI and CABG operations.
The second reason that growth in the PCI sector cannot be entirely explained by the self-referral patterns of cardiologists concerns the volume of CABG procedures performed in the United States and other countries. Based on patient demographic shifts observed after PCI first became available, if the fall in the number of CABG operations being performed today was solely due to greater utilization of stent-assisted PCI, one would expect the number of CABG cases to fall proportionately to the gains in PCI procedures and that those CABG cases that were performed would be more complex.
Neither of these postulates could be confirmed here. During the period of this study, the number of PCIs performed in New York State increased by 20,530. Had all of these new PCI cases occurred because the cardiologists elected to perform PCI rather than refer the patient for a CABG operation, the growth in PCI procedures would have entirely erased New York State's 1997 market of 20,220 CABG cases. Nor did the CABG operations performed in 2003 appear to be more complex. Compared with patients who underwent CABG in 1997, patients who underwent CABG in 2003 were almost identical in terms of percentage of women, isolated CABG, and requirement of an urgent/emergent operation. In fact, one could argue that the CABG cases that were performed in 2003 were less complex. During the 7 years of this study, the number of redo CABG operations in New York State fell 50% from 1335 to 632.
These data suggest that although 5528 fewer CABG cases were performed in New York State, growth occurred in this sector. One source for new CABG case referrals to cardiac surgeons is the PCI procedure itself. Recall that failure of PCI to correct a patient's CAD is an indication for surgery. Although the PCI failure rate is low, with so many more patients receiving PCI, the number of CABG operations performed for early PCI failure (0–2 days) could have stimulated growth in the CABG sector. In this study, early failure of PCI resulted in 125 more patients being referred for surgery in 2003 than in 1997. Late failures of PCI (>2 days) may have also increased the number of referrals; however, the magnitude of growth of the CABG sector because of late failure of PCI cannot be determined from the available pubic information.
In addition, evidence from other health care markets demonstrates that the CABG sector of cardiac services can grow in parallel with the PCI sector. During the period of this study, Canada simultaneously increased its per capita rate of CABG operations by 10%, while doubling the number of PCI procedures performed. Similarly, between 1997 and 2003, the European Union increased its per capita performance of CABG operations by 32%, while increasing the number of PCI procedures performed by 50%.
These observations raise an interesting question: what economic incentives allowed the number of CABG operations performed to increase in Canada and the European Union but to fall in New York State? An answer to this question is suggested by the data from California. Arguably, the laissez-faire market for cardiac services in California is substantially different from the regulated one of New York State. Yet, market shifts in cardiac services observed in California (ie, increasing numbers of PCI procedures/falling numbers of CABG operations) were similar to those noted in New York State. The different growth rates in PCI and CABG performance found in New York, California, Canada, and the European Union could be due to differences in national health care policies. Because the financial incentives in the United States are heavily influenced by Medicare reimbursement benchmarking, one might argue that the divergent finding between New York/California and Canada/Europe with regard to cardiac services is explainable by physician reimbursement. This may be true; however, a more likely explanation can be found in the use of reputational incentives in the United States.
Reputational Incentives. New York State pioneered the use of reputational incentives. Today, a number of states, including California, annually publish physicianspecific outcomes for cardiac services. Other countries, however, have been slow to adopt the use of reputational incentives. Although institution-specific outcomes data for the management of CAD have been available for several years in the European Union, only in April 2006 did the United Kingdom begin to publish surgeon-specific outcomes data for CABG cases.24 Canada, too, has demonstrated a reluctance to publicly disseminate physician-specific outcomes data for cardiac services.25
These national differences in the use of reputational incentives are important because they suggest an explanation as to why CABG volumes are moving in different directions in different health care systems. First, although public reporting of institution-specific outcomes data seems to have little effect on a hospital's market share,6 the evidence in favor of market impact for the use of reputational incentives at the provider level, once considered to be minimal, is becoming increasingly positive.
An early study of Medicare patients in New York State by Peterson and colleagues6 demonstrated that the use of physician-specific reputational incentives (transiently) stimulated patients to seek out-of-state surgeons. Patients' flight to states adjacent to New York for cardiac services proved short-lived, however, perhaps because the first of January publication of mortality rates for cardiac surgeons was forgotten by spring.
Yet, since Peterson published the paper a decade ago, the health care market has changed. The patient safety movement has made it virtually impossible for anyone who reads the newspaper not to hear, on an almost daily basis, how medical errors cause unnecessary patient deaths. Also, making physician-specific outcomes data available on the Internet means that patients who require a CABG in the summer or fall no longer need to go to the library to research their surgeons. These changes and others mean that today's patients no longer blindly accept another doctor's recommendation of a surgeon. Rather, today's patients seem to be almost routinely reviewing a surgeon's clinical report card before agreeing to undergo a surgical operation.
Thus, it is not surprising that more recent studies concerning reputational incentives have demonstrated that the publication of adverse physician-specific outcomes data does have market impact both in America and abroad.26 Jha and Epstein,7 for example, have demonstrated that there is a relationship between a surgeon's ability to work in a community and the dissemination of adverse surgeon-specific outcomes data. In their study, Jha and Epstein examined the reasons that surgeons' names disappeared from the New York State's cardiac surgery reporting system.7 These investigators found that 20% of cardiac surgeons in the quartile with the highest mortality rate ceased practicing in New York during the next 3 years. By comparison, only 5% of cardiac surgeons in the quartile with the lowest mortality rate ceased practicing in New York during the same time period.
Data from the current study compliment the work of Jha and Epstein.7 The negative publicity associated with having one's name appear in the bottom half of a cardiac surgery registry is likely to make a surgeon more reluctant to offer a CABG operation to a patient with a moderate or high risk of death. Fear of being publicly listed as a low-quality surgeon could explain (1) why fewer surgeons in 2003 were willing to take on the more technically demanding challenges of a redo CABG operation and (2) why the patient demographics associated with the risk of operation (eg, female sex, ejection fraction) were not substantially worse than corresponding parameters in 1997. In short, because reputational incentives are sufficient to motivate some surgeons to exit the market, it is reasonable to conclude that reputational incentives are also sufficient to make some cardiac surgeons who want to remain active in New York and California to select their cases with more caution.
Conversely, the lack of use of reputational incentives in Canada and in the European Union offers an explanation of the market shifts in cardiac services in these countries. In New York and California, where reputational incentives are actively employed, surgeons are given an incentive not to operate on high-risk patients. Absent the negative impact of reputational incentives, surgeons in Canada and Europe were freer to earn their living by operating on patients with a greater risk of death. More generally, absent a disincentive to operate, surgeons are given a green light to operate on any case that is referred to them. This is a formula for the overutilization of cardiac services, and it likely accounts for why the number of CABG operations and PCIs are simultaneously increasing in Canada and Europe.
Parenthetically, reputational incentives may explain why cardiac services grew faster than the population in New York State. It is possible that the superior outcomes of surgeons in the top quartile benefited from the publication of positive outcomes. Patients in states adjacent to New York with less well-developed systems for disseminating surgeon-specific outcomes may be migrating to New York State to undergo elective CABG operations from top-rated surgeons. That is, a state's use of reputational incentives is likely to act as a form of free advertising for exceptional cardiac surgeons.