Predicting 6-month mortality risk of patients commencing dialysis treatment for end-stage kidney disease

Abstract

Background: There is evidence that end-stage kidney disease patients who are older or with more comorbidity may have a poor trade-off between benefits of dialysis and potential harms. We aimed to develop a tool for predicting patient mortality in the early stages of receiving dialysis.

Methods: In 23 658 patients aged 15+ years commencing dialysis between 2000 and 2009 in Australia and New Zealand a point score tool was developed to predict 6-month mortality based on a logistic regression analysis of factors available at dialysis initiation. Temporal validation used 2009-11 data from Australia and New Zealand. External validation used the UK Renal Registry.

Results: Within 6 months of commencing dialysis 6.1% of patients had died. A small group (4.7%) of patients had a high predicted mortality risk (>20%), as predicted by the point score tool. Predictive variables were: older age, underweight, chronic lung disease, coronary artery disease, peripheral vascular disease, cerebrovascular disease (particularly for patients <60 years of age), late referral to nephrologist care and underlying cause of renal disease. The new point score tool outperformed existing models, and had an area under the receiver operating characteristic curve of 0.755 on temporal validation with acceptable calibration and 0.713 on external validation with poor calibration.

Conclusion: Our point score tool for predicting 6-month mortality in patients at dialysis commencement has sufficient prognostic accuracy to use in Australia and New Zealand for prognosis and identification of high risk patients who may be given appropriate supportive care. Use in other countries requires further study.

Keywords: 6-month mortality; comorbidity; dialysis; end-stage kidney disease.