Introduction: Despite numerous studies exploring survival outcomes among patients undergoing dialysis, particularly those awaiting kidney transplantation from deceased donors (KTDD) on national kidney transplant (KT) waiting lists (WL), our study represents the inaugural investigation of its kind in Tunisia. It concentrates on assessing mortality risk factors among patients registered on the national WL within the Department of Internal Medicine "A" at Charles Nicolle Hospital in Tunis.
Method: This retrospective cohort study targeted patients with end-stage renal disease who were monitored in the Internal Medicine "A" department and placed on the national WL. Data were collected from January 1, 2001 to December 31, 2022. Patients were observed from their initial placement on the WL until death, last follow-up available, or the end of the study period. Patients who underwent KT elsewhere in Tunisia or abroad were excluded from the analysis. We utilized univariate and multivariate Cox proportional hazards regression analyses to assess survival outcomes post-WL placement.
Results: During the study period, a total of 787 patients were listed on the WL, with 42.6% being female and the mean age recorded at WL registration being 38.9±11.4 years. Among these patients, 65.4% had hypertension, 5.7% were diabetic and KTDD was performed for 12.5% of them.
The death rate among registered patients was 37.1%, with 41.1% not being transplanted at the study's end and 27.5% receiving a kidney from a DD. The mean age of death was 50.37 ± 12.3 years for not transplanted patients and 48.1 ± 8.4 years for KT recipients. The primary causes of death were cardiovascular diseases (CV) (35%) and infectious causes (32.5%) for patients on dialysis, while KT recipients died from infectious causes (57.1%) and CV diseases (21.4%).
In the univariate analysis, a lower risk of death was associated with transfusions (HR=0.76 [CI: 0.59-0.98]), serum albumin levels >35 g/L (HR=0.65 [CI: 0.47-0.9]), updated pre-transplant assessments (UPTA) (HR=0.58 [CI: 0.45-0.75]), and KTDD (HR=0.43 [CI: 0.29-0.64]). Shorter survival was observed among patients aged 35-50 years (HR=2.79 [CI: 1.68-4.64]) and >50 years (HR=6.49 [CI: 3.73-11.35]) at dialysis initiation, patients with diabetes (HR=3.59 [CI: 2.44-5.3]), hypertension (HR=1.34 [CI: 1.03-1.76]), CV diseases (HR=1.65 [CI: 1.01-2.69]), a history of pregnancy (HR=1.75 [CI: 1.15-2.67]), and body mass index >30 kg/m2 (HR=2.73 [CI: 2.18-6.32]).
In the multivariate analysis, KTDD (HR=0.27 [CI: 0.1-0.75]) and UPTA (HR=0.34 [CI: 0.14-0.8]) were associated with improved survival outcomes.
Conclusion: In summary, our study has highlighted the importance of KTDD and regular updating of UPTA in improving the survival of patients on the KT WL. However, challenges persist related to patient age and comorbidities. Further research is needed to better understand these associations and develop clinical strategies to improve survival outcomes for patients awaiting KTDD.