Survival of Patients on Hemodialysis and Predictors of Mortality: a Single-Centre Analysis of Time-Dependent Factors

Abstract

Introduction. This study aimed to evaluate the outcome and predictors of survival in hemodialysis patients of Hasheminejad Kidney Center where a comprehensive dialysis care program has been placed since 2004.

Materials and Methods. Data of 560 hemodialysis patients were used to evaluate 9-year survival rates and predictors of mortality. Cox regression models included comorbidities as well as averaged and 6-month-averaged time-dependent values of laboratory findings as independent factors.

Results. Survival rates were 91.9%, 66.0%, 46.3%, and 28.5%,  at 1, 3, 5, and 9 years, respectively, in all patients and 90.8%, 61.6%, 42.1%, and 28.0% in 395 incident patients starting hemodialysis after 2004. Adjusted survival models demonstrated age, male sex, diabetes mellitus, cardiovascular disease, and high-risk vascular access as baseline predictors of mortality, as well as averaged low hemoglobin level (hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.36 to 2.90) and a single-pool KT/V < 1.2 (HR, 2.28; 95% CI, 1.60 to 3.26). The averaged high-density lipoprotein cholesterol (HR, 0.67; 95% CI, 0.55 to 0.81) and serum creatinine (HR, 0.71; 95% CI, 0.64 to 0.79) levels demonstrated protective effects. The adjusted time-dependent model further revealed the significant association of hypocalcemia (HR, 1.63; 95% CI, 1.13 to 2.34), hypercalcemia (HR, 1.50; 95% CI, 1.02 to 2.21), and hyperphosphatemia (HR, 1.68; 95% CI, 1.20 to 2.37) with death.

Conclusions. Our patients have relatively comparable survival rates with high-profile dialysis centers. Aiming to better achieve the recommended targets, especially hemoglobin and nutritional and bone metabolism factors, should be considered for optimal dialysis outcomes.