Mortality Rates and a Clinical Predictive Model for the Elderly on Maintenance Hemodialysis: A Large Observational Cohort Study of 17,354 Asian Patients

Abstract

INTRODUCTION: Mortality following hemodialysis initiation may influence the decision to initiate hemodialysis in elderly patients. Our objective is to demonstrate mortality following hemodialysis initiation in elderly patients (≥70 years) and to derive a prediction risk score based on clinical and laboratory indicators to determine risk of all-cause mortality in patients aged ≥80 years. METHODS: We identified elderly patients (≥70 years) who initiated maintenance hemodialysis between January 2005 and December 2016 using data from the Thai Renal Replacement Therapy (TRT) registry. The mortality rate was determined based on age categories. A predictive risk score for all-cause mortality was created for 4,451 patients aged ≥80 years by using demographics, laboratory values, and interview-based parameters. Using a flexible parametric survival analysis, we predicted mortality 3 months, 6 months, 1 year, 5 years, and 10 years after hemodialysis initiation. RESULTS: 17,354 patients (≥70 years) were included, mean age 76.9 ± 5.1 years, 46.5% male, and 6,309 (36.4%) died. Patients aged <80 years had a median survival time of 110.6 months. A 9-point risk score was developed to predict mortality in patients aged ≥80 years: age >85 years, male, body mass index <18.5 kg/m2, hemoglobin <10.0 g/dL, albumin <3.5 g/dL, substantial assistance required in daily living (1 point each), and Karnofsky Performance Status (KPS) score <50 (3 points). C-statistic of 0.797 indicated high model discrimination. Internal validation demonstrated good agreement between observed and anticipated mortalities. CONCLUSIONS: Hemodialysis is appropriate for patients aged 70-80 years. A risk score for mortality in patients aged ≥80 years has been developed. The score is based on seven readily obtainable and evaluable clinical characteristics.