The purpose of this study was to assess the extent to which non-medical factors explain differences in transplant rates between racial and gender categories.

Subjects for this study consisted of all black or white patients receiving treatment for end stage renal disease (ESRD) at dialysis centers in three states as of January 1989 and patients who began receiving treatment during the eight months after January 1989. Data were obtained from a registry that was based primarily on staff questionnaires.

Among the 8315 patients, 1280 (15.4%) were classified by their dialysis facility as transplant candidates. Transplant candidacy was associated with younger age, male sex, white race, and higher SES (by several measures). Additionally, patients with diabetic ESRD and patients who were receiving dialysis for at least two years were less likely to be considered transplant candidates. Finally, impaired functional status, nutritional impairment, and presence of comorbid conditions were also associated with lower likelihood of being selected for candidacy. In multivariate regression, controlling for all of these factors, racial group was still associated with candidacy: the odds ratio (OR) for black males versus white males was 0.77 (0.59-0.99) and the OR for black females versus white males was 0.66 (0.51-0.87).

The transplant candidacy measure used in this study reflects the opinion of the patient’s dialysis center regarding the current transplant status of the patient; it is best regarded as an indication of how those carding for the patient categorize his or her transplant prospects. However it is unclear whether the transplant candidacy was based solely on clinicians’ decisions or whether patient preferences influenced this choice as well. It is also uncertain how patients with live donor opportunities were handled in this analysis.

The authors speculates that the association between SES measures and candidacy selection might be explained by communication barriers; differences among patient opinions, attitudes and beliefs; perceived access to transplant; economic barriers; social roles; patient preference or refusal of referral; noncompliance with dialysis; and inability to cooperate with post-transplant medication. They further add that dialysis center characteristics (staff attitudes regarding transplantation, physician training, access to transplant centers, and so on) may affect transplant status.

The authors do not suggest explanations for the race association, other than stating, “efforts to understand the differences in transplantation relates among different race-sex groups must consider the possibility that there are other factors associated with these groups that influence the referral of patients for transplant evaluation.”