This research examines factors contributing to the disparity in access to high-quality cardiac surgeons that blacks face in NYS. The analysis demonstrates that the physician providing most of the cardiac care before surgery may contribute up to 30 percent to the differential in the quality of surgeons treating blacks and whites, after controlling for patient clinical and socio-economic characteristics. It further shows that the process involving this physician contributes in two ways. First, blacks are accessing a subset of all physicians, and this group of physicians is associated with a subset of the surgeons, a subset that has higher RAMR. Second, white and black patients seen by the same physician are referred to different surgeons. The latter effect diminishes if the physician refers more blacks to CABG surgery or if the surgery is performed in a hospital to which the physician directs most of his or her business.
With the data available to us we cannot determine if the referral decision was made by the physician or the patient. It is possible that physicians offer their white and black patients the same panel of surgeons but that black patients choose those who have higher RAMR because of other characteristics that are of more importance to them—e.g., distance.
A tradeoff between surgeon quality and other attributes is a legitimate aspect of the choice as long as it is made by a fully informed patient. The question is whether blacks are indeed fully informed when they make the decision, or whether race affects the interaction between the patient and the physician, and in some ways impedes the full transfer of information when the patient is black. Johnson et al. (2004)
found that there are differences in the interaction between patients and their physicians. When the patient was black, the interaction was less patient-centered and more dominated by the physician, and physicians exhibited a lower level of positive affect. Therefore, it is possible that blacks do not receive the same information about their referral choice as do white patients. If they are not informed about the surgeon's RAMR or do not understand the information, then they may give it less weight than whites, and thus end up making choices that are skewed away from the best surgeons.
The finding that the within-physician disparity decreases with the number of black patients referred to CABG might be an indication that those physicians who deal with more black patients have learned how to impart information better to their black patients, and thus their patients are making choices that are more similar to those made by whites. It may also be the result of patient selection. Blacks may prefer physicians who would refer them to better surgeons. Thus, at the time they choose a cardiologist (node 1 in ) they choose a physician who is more likely to refer them to a better surgeon. It is unclear how likely this latter process is, as it is questionable whether patients have information about the referral patterns by race of the various cardiologists available to them.
Our data also do not include information about the race of the physician, yet this may explain the higher RAMR for the panels of physicians referring blacks compared with those referring only white patients (the across-physician variation). Hargraves, Stoddard, and Trude (2001)
found, based on the Community Tracking Study Physician Survey, that more minority physicians report having difficulty getting medically necessary referrals to high-quality specialists for their patients and have more difficulty admitting them to a hospital. Moy and Bartman (1995)
report based on the 1987 national Medical Expenditures Panel Survey, that minorities are four times more likely than whites to identify a minority physician as their usual source of care. If these patterns hold for our cohort, i.e., if the majority of blacks in our study have black physicians, physicians who face difficulty referring to high-quality specialists, then it would explain our finding of higher RAMR for their panels.
Such patterns may also explain our finding that blacks are referred to higher quality surgeons if they are cared for in the hospital to which the physician refers most of her or his cardiac patients. The physician is likely to have more clout in a hospital to which he or she makes many referrals, clout that can be translated into being able to refer patients to the best surgeons. Furthermore, if the physician refers many patients to the same hospital, then the physician is more likely to know the surgeons and their performance and thus is better able to make a referral based on the surgeon's quality.
To summarize, we find that several pathways, which depend on the physician the patient saw before surgery, lead blacks to the lower quality cardiac surgeons. Further research is required to determine whether the hypotheses we offer to explain these pathways do indeed contribute to the differences in referrals for blacks. Such information would help guide specific policies that could ameliorate these disparities. One policy that might effectively address all of these pathways is to publish a report card on referral patterns. Whether the reasons for differences in referrals are due to interaction between physicians and their patients, physicians and the surgeons and the hospitals, or the initial choice of cardiologist, increasing awareness of the existence of differences in referral patterns may influence the behavior of all involved.