Understanding racial/ethnic differences in breast cancer-related physical well-being: the role of patient-provider interactions.

Purpose: Racial/ethnic differences in cancer symptom burden are well documented, but limited research has evaluated modifiable factors underlying these differences. Our objective was to examine the role of patient-provider interactions to help explain the relationship between race/ethnicity and cancer-specific physical well-being (PWB) among women with breast cancer.
Methods: The Pathways Study is a prospective cohort study of 4505 women diagnosed with breast cancer at Kaiser Permanente Northern California between 2006 and 2013. Our analysis included white, black, Hispanic, and Asian participants who completed baseline assessments of PWB, measured using the Functional Assessment of Cancer Therapy for Breast Cancer, and patient-provider interactions, measured by the Interpersonal Processes of Care Survey (IPC) (N = 4002). Using step-wise linear regression, we examined associations of race/ethnicity with PWB, and changes in associations when IPC domains were added.
Results: We observed racial/ethnic differences in PWB, with minorities reporting lower scores than whites (beta, black: - 1.79; beta, Hispanic: - 1.92; beta, Asian: - 1.68; p < 0.0001 for all comparisons). With the addition of health and demographic covariates to the model, associations between race/ethnicity and PWB score became attenuated for blacks and Asians (beta: - 0.63, p = 0.06; beta: - 0.68, p = 0.02, respectively) and, to a lesser extent, for Hispanic women (beta: - 1.06, p = 0.0003). Adjusting for IPC domains did not affect Hispanic-white differences (beta: - 1.08, p = 0.0002), and slightly attenuated black-white differences (beta: - 0.51, p = 0.14). Asian-white differences narrowed substantially (beta: - 0.31, p = 0.28).
Conclusions: IPC domains, including those capturing perceived discrimination, respect, and clarity of communication, appeared to partly explain PWB differences for black and Asian women. Results highlight opportunities to improve providers' interactions with minority patients, and communication with minority patients about their supportive care needs.