Objectives: To identify the demographic, clinical and psychosocial characteristics associated with racial differences in willingness to receive cyclophosphamide (CYC) or participate in a research clinical trial (RCT) among patients with systemic lupus erythematosus (SLE).
Methods: Data from 163 African-American (AA) and 180 white (WH) SLE patients were evaluated. Structured interviews and chart reviews were conducted to determine treatment preferences in hypothetical situations and identify variables that may affect preferences. Logistic regression models were performed to evaluate the relationship between patient preferences and race, adjusted for patient characteristics.
Results: Among patients who had never received CYC (n=293), 62.9% AAs compared to 87.6% WHs were willing to receive the medication (p<0.001). This difference persisted (OR 0.37 [95% CI, 0.16-0.87]) after adjusting for socio-demographics, clinical characteristics, and perceptions about CYC and physicians. Income and higher perception of CYC effectiveness were other determinants of willingness to receive CYC. Among patients who had never participated in an RCT (n=326), 64.9% AAs compared to 84.3% WHs were willing to do so (p<0.001). This difference persisted (OR 0.41 [95% CI, 0.20-0.83]) after adjusting for socio-demographics, clinical context and patients' perceptions of physicians. SLE damage score, number of immunosuppressive medications and higher trust in physicians were also independently associated with willingness to participate in an RCT.
Conclusions: Race remains an independent determinant of treatment preferences after adjustment for income, medications, medication efficacy expectations and trust in physicians. While some factors related to racial differences in preferences are relatively fixed, others that may alleviate these differences also exist, including medication beliefs and provider trust.