In another study based on actual clinical encounters, van Ryn and Burke (2000) surveyed 193 physicians to assess their perceptions of 842 patients (57% white and 43% African American) following post-angiogram hospital visits. The authors asked physicians to rate their patients on a variety of personal characteristics such as intelligence, self-control, education level, pleasantness, rationality, independence, and responsibility. In addition, the authors asked physicians to rate their feelings of affiliation toward the patient and their perceptions of their patients' degree of social support, tendencies to exaggerate discomfort, likelihood of complying with medical advice, likelihood of drug or alcohol abuse, as well as other characteristics.
van Ryn and Burke also surveyed patients and assessed their frailty/sickness, depressive symptoms, social assertiveness, feelings of self-efficacy, and perceived social support. These variables, along with information about physicians' age, sex, race, and medical specialty were entered into logistic regression analyses to control for the impact of these variables on physicians' assessments of patients.
The results supported the authors' hypotheses that patient race and socioeconomic background do influence physicians' perceptions, even when controlling for differences in patients' socioeconomic status, personality attributes and degree of illness. African-American patients were rated as less intelligent, less educated, more likely to abuse drugs and alcohol, more likely to fail to comply with medical advice, more likely to lack social support, and less likely to participate in cardiac rehabilitation than white patients. Furthermore, African-American patients were two-thirds as likely as whites to be perceived as the kind of person the physician could see him/herself being friends with. Finally, a significant interaction of race and socioeconomic status was found, in that at low socioeconomic (SES) levels, black patients were rated as less pleasant and less rational than whites.
These studies lend support to the hypothesis that physicians' diagnostic and treatment decisions are influenced by patient race. In addition, they suggest that these influences are complex, and that both patient and provider gender may significantly influence physicians' perceptions. They do not, however, elucidate the mechanisms by which these attitudes, biases, and stereotypes may result in differences in clinical treatment, or the degree to which these attitudes might affect the outcome of patient care. It therefore remains unclear what degree of racial and ethnic disparities may be explained by this mechanism.