This study was conducted to determine if there is evidence of differences between black and white patients in willingness to undergo carotid endarterectomy. Willingness to undergo the procedure (defined as the additional risk of death a patient would accept to avoid endarterectomy as a therapy for a hypothetical situation) was assessed for a sample of male patients at least 45 years old who were hospitalized during the period from January 1994 to May 1995 at one of four Veterans Affairs centers (Durham, Pittsburgh, St. Louis, and West Los Angeles) for transient ischemic attacks or ischemic stroke. Although there were no racial differences in response rates to the invitation to participate in the study, response rates varied across the sites: 62% in Durham, 65% in Pittsburgh, 51% in St. Louis, and 33% in West Los Angeles.

Data were collected from patient interviews and medical record reviews. Willingness to undergo the procedure was assessed using the standard gamble technique in which the patient was asked to choose between undergoing surgery and taking a pill. The risk of death from surgery and probability of success of surgery were set at 5% and 95% (respectively). These risks were systematically varied for the pill as follows: the risk of death for the pill began at 50%, and then decreased by 10 percentage points in successive questions. The questioning stopped when the patient either became indifferent as to whether he should take surgery or the pill or chose surgery. The excess risk of death a patient was willing to accept to avoid surgery was estimated based on the patient’s responses to this series of questions.

Although age, marital status, education, employment status, Charlston comorbidity scores, Barthel functional status index, and current health perceptions were similar between blacks and whites, there were a number of clinical differences. These differences included: a smaller proportion of African Americans had a history of transient ischemic attacks during or before the index hospitalization (25% versus 58%, p<0.01), a greater proportion of African Americans were hospitalized for stroke (75% versus 33%, p<0.01), and a smaller proportion of African American patients had their carotid arteries imaged by either carotid ultrasound or angiography during the index hospitalization (67% versus 93%, p<0.01). Two of the 44 African American and nine of the 46 white patients underwent carotid endarterectomy.

African American patients were willing to accept more excess risk of death to avoid carotid endarterectomy compared with whites (median excess risk: 20% for African Americans versus 2.5% for whites, p=0.01). Most white respondents had excess risk scores between 0 and 2.5%, generally indicating that they would prefer to take the pill if it carried the same risk of death as the surgery, but not if it carried a greater risk. African American patients had a bimodal distribution of excess risk with substantially greater and more widely dispersed excess risk scores: one was 0 to 2.5% range and a second peak was in the 20% to 40% range. This second pattern of the excess risk score suggests a much greater desire to avoid the procedure among African Americans. Exclusion from the sample of all patients who received a carotid endarterectomy did not change this association. The pattern also did not change when patients were stratified according to clinical state at the time of hospitalization.

The authors then tested a secondary hypothesis that prior surgical experiences as well as the value that patients placed on their current health state independent of their clinical diagnosis would alter their aversion to endarterectomy. While there were racial differences in having had surgical experience (73% of African Americans versus 94% of whites had had prior surgery, p=0.01), there was no racial difference in patients’ perception of the success of past surgeries (91% of African Americans versus 88% of whites rate their past surgeries as successful, p=0.94). In a multivariate analysis, African American race, having had no prior history of prior surgery, and lower rating for current health state all predicted greater aversion to endarterectomy.

While this study advanced the understanding of the potential influence of patient choice on racial disparities in surgical procedures, there were several limitations. First, the sample size was small and the refusal rate was large, limiting the generalizability of these results. Additionally, clinical and treatment differences between blacks and whites may have influenced the results. However, the authors attempted to adjust for current health status and the similarity of severity scores and consistency of the findings within disease categories suggest this is unlikely. Third, the authors were assessing the patient’s aversion to undergoing a hypothetical procedure, rather than assessing the patient’s actual clinical choices. It is possible that, given a group of patients with a similar history and similar clinical characteristics, racial variation in actual surgical decisions might differ from the results presented here. Fourth, the prior advice of the physicians was not measured. It is possible that physicians of black patients did not recommend this procedure to their patients as highly as the physicians of white patients, thus explaining these findings.

The authors conclude that this study showed blacks have a greater aversion to undergoing carotid endarterectomy than whites and that elucidating the reasons for this difference are of crucial importance. “A particularly essential future area of investigation is understanding the reasons for these differences in aversion toward surgery and how the presentation of information concerning the risks and benefits of endarterectomy and other procedures can influence patients’ decisions about accepting these procedures.”