Background: Prognostic assessment after starting hemodialysis is challenging, with mortality in the first year estimated to be 15%. Clark et al. developed the Recovery and Death Outcome risk score, which accurately predicted the likelihood of renal recovery to dialysis independence and of death within 1 year after in-hospital dialysis initiation, respectively. We aimed to validate the Death Outcome risk score to predict one-year mortality after dialysis start in our population.

Methods: Retrospective analysis of hospitalized patients starting hemodialysis in a tertiary-care hospital from January 1st, 2016, to December 31st, 2019. All-cause mortality risk one year after discharge was calculated according to the ReDO Death score. Patients were classified into death outcome risk groups and Cox regression was used to determine if the risk score was predictive of one-year mortality. The discriminatory ability for the ReDO Death score to predict mortality was determined using the receiver operating characteristic (ROC) curve.

Results: 369 patients were included, mostly male (59.9%), with mean age 71.1 ± 14.3 years and median Charlson score 7±3. The one-year mortality rate was 22.2%. The ReDO Death score accurately predicted the one-year risk of mortality, with an area under the ROC of 0.741, [95% CI (0.687–0.794), p<0.001]. The optimal REDO Death risk cut-off was >30%, with a hazard ratio of 6.57 [95% CI (3.48–12.2), p<0.001] for one-year mortality risk (sensitivity 78.0% and specificity 60.6%).

Conclusion: We validated the ReDO Death score for 1-year mortality prediction after starting hemodialysis during hospitalization in a Portuguese population. This score can be used as a tool to inform goals-of-care discussion at the time of transition to out-of-hospital care.