Re: Disparities in Utilization of Autologous Hematopoietic Cell Transplantation for Treatment of Multiple Myeloma.

Costa et al. recently reported that racial disparities prevented nearly 40% of non-Hispanic blacks with multiple myeloma (MM) from undergoing stem cell transplantation (SCT), but the authors were unable to provide an explanation for the disparities because of limitations of their datasets. They hypothesized that socioeconomic status (SES) and/or insurance providers might account for the disparity. To examine the issue raised by Costa et al., we performed a secondary analysis using hierarchical multivariate logistic regression with data previously collected to determine if age at diagnosis, sex, SES, primary insurance provider at diagnosis, and comorbidity score help explain the racial disparities in SCT utilization. A model of race, age, sex, SES, insurance provider, and comorbidity score was the most accurate model in predicting stem cell utilization status (χ(2)[12] = 193.859; P < .001; area under the curve = .837; P < .001). After controlling for the covariates, black patients were less likely to undergo SCT than white patients (adjusted odds ratio, .49; 95% confidence interval, .27 to .89; P = .013). In conclusion, we also observed racial disparities between black and white patients with MM in SCT utilization and these are not fully accounted for by the covariates age, sex, SES, insurance provider, and comorbidity score.