Poorer graft survival in ethnic minorities: results from a multi-centre UK study of kidney transplant outcomes

Background: The STEPP group was established to investigate factors that affect long-term transplant outcomes including quality of life and other patient-reported outcomes between different transplant centers and patients. Methods: Data were collected for 2,650 patients whose first renal transplant took place between 1992 and 2003 in five UK centers. Univariable and multivariable survival analyses were performed using eleven candidate explanatory variables. Results: Graft survival was worse in Black (B) patients (HR B v W 1.57 95% Cl 1.10, 2.24), and in South Asian (A) patients (HR A v W 1.39 95% Cl 1.03, 1.85) compared to Whites (W) after adjusting for other factors including HLA mismatch, and time on dialysis. Time spent on dialysis pre-transplantation was non-linearly associated with patient, but not death-censored graft survival. Losing a functioning graft was a strong predictor of patient death. One site had both the best graft and the worst patient survival. Conclusions: Differences in patient and graft survival between ethnic groups cannot be explained by currently recognized factors. These, and the complex balance between optimum patient and graft survival which differs between sites in this study require further investigation.