Clinical assessment of mortality risk in renal transplant candidates in Spain

Prediction of mortality in wait-listed patients for kidney transplantation (KT) has not been well elucidated. We assessed whether application of the Charlson comorbidity index (CCI) and other uremia-related comorbidities, not included in the CCI, were associated with mortality in these patients.

We included 3851 adult patients from the Andalusian Registry who were placed on the waiting list for KT during the study period (1984-2012). A total of 1975 patients received a successful KT and were censored at that point, whereas 1876 were on the waiting list at any time. Multivariate Cox proportional regression analysis and competing risk models, both of which included a propensity score for factors leading to KT, were constructed to examine death in wait-listed patients.

Overall mortality on the waiting list was 24%, and cardiovascular disease was the leading cause of death (25%), followed by infections (19%) and malignant disorders (7%). By competing risk models, age older than 50 years (subhazard ratio [SHR] 1.4; 95% CI, 1.1-1.9), CCI score higher than 3 (SHR 2.8; 95% CI, 2.1-3.7), a central venous catheter (SHR 1.8; 95% CI, 1.4-2.2) and unemployed status (SHR 1.7; 95% CI, 1.3-2.2) at dialysis entry were significantly associated with mortality. When these factors were incorporated in a composite risk model, mortality risk increased significantly with increasing risk levels.

A limited number of comorbidities, easily measurable at entry to dialysis, are associated with mortality in wait-listed patients. This simple clinical assessment may help prioritize high-risk wait-listed patients for receiving an age-matched deceased donor kidney.