Is decedent race an independent predictor of organ donor consent or merely a surrogate marker of socioeconomic status?

Background: Studies have demonstrated that African American race is a strong predictor of nondonation. However, it is often and correctly argued that African American race is a crude explanatory variable that is a surrogate marker of socioeconomic status, education, and access to health care. We hypothesized that, when controlling for these factors, African American race would cease to be a predictor of organ donation. Methods: A retrospective review of 1292 Alabama decedents who were approached for organ donation between 2006 and 2009 was performed. Multivariable logistic regression models were constructed to identify the most parsimonious model that could explain the variation in the log odds of obtaining consent. Results: Consent for donation was obtained from 49% of the decedents' families. Household income was a predictor of organ donor consent only in whites. Surprisingly, household income was not statistically different between consented and nonconsented African American decedents (U.S. $25,147 vs. U.S. $26,137, P=0.90). On multivariable analysis, education, urban residence, and shorter distance between the decedent's residence and donor hospital were significantly associated with obtaining consent for organ donation. On univariate analysis, the odds ratio of donor consent in whites compared with African Americans was 2.76 (95% confidence interval, 2.17-3.57). When controlling for socioeconomic status and access to health care variables, the odds ratio of donor consent increased to 4.36 (95% confidence interval, 2.88-6.61). Conclusions: We interpret this result to indicate that there remains unknown but important factor(s) associated with both race and obtaining organ donor consent. Further studies are required to isolate and determine whether this factor(s) is modifiable.