Evaluation of Long-term Survival and Predictors of Mortality in Hemodialysis Patients by Using Time Dependent Variables, A Single Centre Cohort Analysis

Abstract

Introduction. Despite significant improvement in End Stage Kidney Disease (ESKD) patient’s management, and better availability of dialysis for caregivers, mortality among these patients is unacceptably high. Methods. We collected the data of 751 incident hemodialysis patients from March 2004 to November 2018. Survival curves was created by using the Kaplan-Meier method. Comorbidities, as well as time-dependent values of laboratory findings, were examined as independent factors by three models of Cox regression analysis. Results. The median follow-up period was 31.7 months (1.08 to 169.28). Patient survival rates were 88%, 77%, 56%, 32%, 26% ,16% and 12%, at 1, 2, 4,6, 8, 10, 12 and 14 years of follow-up, respectively. The most common cause of mortality was cardiovascular disease. We observed lower survival rates in patients ≥ 65 years (HR = 2.684, 95% CI: 1.133 to 3.377; P < .001), diabetes mellitus (HR = 1.729, 95% CI: 1.484 to 2.014; P < .001) and walking disability (HR = 2.505; 95% CI: 2.104 to 2.983; P < .001). Low hemoglobin level (HR = 1.496; 95% CI: 1.257 to 1.779; P < .001), hyperphosphatemia (HR = 1.305, 95% CI: 1.104 to 1.542; P = 0.002) and high low-density lipoprotein cholesterol level (HR = 1.933; 95% CI: 1.431 to 2.611; P < .001) were predictors of mortality. A single pool Kt/V > 1.2 (HR = 0.743, 95% CI: 0.635 to 0.870; P < .001) and high serum creatinine level (HR = 0.842, 95% CI: 0.811 to 0.874; P < .001) showed protective effects. Conclusion. Our study showed a high survival rate in a single center cohort of hemodialysis patients in Iran. Traditional risk factors of mortality in general population, as well as indices of dialysis efficacy and general health status were the main predictors of mortality. Nationwide registries are necessary to investigate the dialysis survival rates and their predictors in our country.

DOI: 10.52547/ijkd.6435