Analysis of mortality while on waiting list for kidney transplant in adults in Argentina 2005-2009

Abstract

Introduction: Comparison of survival after renal transplant patients on the waiting list is an important factor to evaluate this therapy.

Objective: To measure the magnitude of deceased donor kidney transplant on patient survival compared to patients on dialysis and on waiting lists in over 18 years in Argentina.

Material and methods: The information was obtained from SINTRA for the period January 2003 to December 2009. The follow-up period ended in December 2010. Survival was considered as the time from the entrance to the waiting list until death, the end of the study (June 2009), or last follow-up available, whichever came first. The Kaplan-Meir method was used. The survival rate was recorded at 30 days, 1, 5 and 10 years. Log-rank was used to compare the curves and their statistical significance. The Cox regression model was used to consider the variables for both patient and graft survival, such as gender and age, time on dialysis, etiology of end-stage renal disease (ESRD), and presence of comorbidities. The MedCalc and SPSS 17 statistical packages were used.

Results: We analyzed 1682 patients transplanted average age 48.14 + 13.48 years and 3647 patients on waiting lists average age 47.88 + 14.32 years. For patients transplanted 30-day survival was 99.8% at 1 year 96.2% and 5 years of 79.9%. For patients on the waiting list survival at 30 days was 99.7% at 1 year and 5 years 94.6% 66.6%. Chi-square was 42.77, P = <.0001. HR 0.64 (95% CI 0.56 to 0.73). Cox regression for patients on waiting lists HR 1.40 (95% CI 1.20-1.63) P = <.0001. The time dependent Cox regression showed for patients transplanted at 30 days, <1 year >1 year showed HR 4.18 (95% CI 2.88-6.06) P = <.0001, HR 0.40 (95% CI 0.27 to 0.61) P = <.0001 and HR 0.19 (95% CI 1.12-0.29) P = <.0001, respectively.

Conclusions: Survival, both at baseline and in the long term, is better in transplant patients as compared to patients on waiting list. In Cox time-dependant regression the risk of death during the first 30 days is 4 times higher in transplant patients. This reverses and at 1 year, transplant patients are 60% less likely to die, and after one year this probability is 81% lower (P =<.0001).