Epidemiology of dialysis-treated end-stage renal disease patients in Kazakhstan: data from nationwide large-scale registry 2014-2018

Abstract

Background: The epidemiology of dialysis patients has been little studied in developing countries and economies in transition. We examined the prevalence, incidence and mortality rate of dialysis patients in Kazakhstan, via aggregation and utilization of large-scale administrative healthcare data.

Methods: The registry data of 8898 patients receiving dialysis therapy between 2014 and 2018 years were extracted from the Unified National Electronic Health System (UNEHS) and linked with the national population registry of Kazakhstan. We provide descriptive statistics of demographic, comorbidity and dialysis-related characteristics.

Results: Among all patients undergoing maintenance dialysis for end-stage renal disease (ESRD), there were 3941 (44%) females and 4957 (56%) males. 98.7% of patients received hemodialysis and 1.3% peritoneal dialysis. The majority of the patients (63%) were ethnic Kazakhs, 18% were Russians and 19% were of other ethnicities. The prevalence and incidence rate in 2014 were 135.2 and 68.9 per million population (PMP), respectively, which were different in 2018 [350.2 and 94.9 PMP, respectively]. Overall mortality rate among dialysis patients reduced from 1667/1000 patient-years [95%Confidence Interval (CI): 1473-1886] (PY) in 2014 to 710/1000PY [95%CI: 658-767] in 2018. We observed 13% lower crude survival probability in females compared to males and in older patients compared to younger ones. Russian ethnicity had 58% higher risk of death, while other ethnicities had 34% higher risk of death compared to in those of Kazakh ethnicity.

Conclusion: We describe for the first time in Kazakhstan an increase in the prevalence and incidence of ESRD on dialysis, while mortality rate decreased over time, during 2014-2018. We observed statistically significant lower survival probability in female dialysis patients compared to males, in older patients compared to younger ones, and in patients of Russian ethnicity compared to Kazakh.

Keywords: Dialysis; ESRD; Epidemiology; Kazakhstan; Registry.

Fig. 1

Prevalence, incidence and mortality of dialysis patients for 2014–2018 years

Fig. 2

Crude mortality rate among dialysis population for 2014–2018 years

Fig. 3

Crude survival probability on dialysis by gender (a), ethnicity (b), age category (c) and education level (d). *Unadjusted Cox proportional hazard regression analysis. Abbreviations: ISCED - International Standard Classification of Education; HR – hazard ratio

Fig. 4

Cumulative incidence of transplant censored all-cause death on dialysis by gender (a) and ethnicity (b). *Unadjusted competing risk regression analysis. Abbreviations: SHR – subdistribution hazard ratio