Analysis of mortality risk from Korean hemodialysis registry data 2017

Abstract

The End-stage Renal Disease Registry Committee of the Korean Society of Nephrology collects data on the dialysis therapy in Korea through an internet-based registry program and reports it annually. In this article, the method and clinical implications of the mortality hazard ratio analyses of various clinical parameters in the 2017 registry report have been described, with the inclusion of data on four additional parameters. The mortality risk based on clinical parameters was analyzed only for hemodialysis patients. The number of registered patients with laboratory data was 13,943 (8,446 male and 5,497 female patients), and death was reported in 3,139 patients. Analysis of the effects of various clinical parameters on mortality was performed using non-linear Cox proportional hazard model with the R statistics program. For all clinical parameters, univariate and adjusted multivariate hazard ratio analyses were performed. Analysis of the mortality hazard ratio showed that low body mass index, low hemoglobin, low serum albumin, low serum phosphorus, and low urea reduction ratio were associated with a significantly increased mortality risk, whereas paradoxically high serum creatinine levels were associated with low mortality risk.

Keywords: Chronic kidney failure; Dialysis; Mortality.

Figure 1. Mortality hazard ratio according to age distribution

Age, as a continuous variable on the x-axis, and the overall hemodialysis patient number distribution bar graph overlapped (right y-axis); horizontal line is at hazard ratio 1.0. DM, diabetes mellitus.

Figure 2. Mortality hazard ratio according to blood pressure distribution

Gray shade around the hazard ratio line represents 95% confidence interval. (A) Systolic blood pressure. (B) Diastolic blood pressure.

Figure 3

Mortality hazard ratio according to body mass index distribution.

Figure 4

Mortality hazard ratio according to hemoglobin distribution.

Figure 5. Mortality hazard ratios according to blood biochemical parameters

(A) Serum creatinine. (B) Serum albumin. (C) Serum calcium. (D) Serum phosphorus. (E) Total cholesterol. (F) Hemoglobin A1c. (G) Intact-parathyroid hormone. (H) Serum uric acid.

Figure 6. Mortality hazard ratio according to dialysis adequacy

(A) Urea reduction ratio. (B) Single pool Kt/V.

Figure 7. Adjusted multivariate mortality hazard ratio analyses of various clinical parameters and comparisons of hazard ratio between the third and the first quarter values of each parameter

BMI, body mass index; BP, blood pressure; DM, diabetes mellitus; HbA1c, hemoglobin A1c; PTH, parathyroid hormone; spKt/V, single pool Kt/V; URR, urea reduction ratio. *The parameters are not statistically significant.