Kidney Week

Abstract: TH-PO418

Survival of Patients with CKD Stages 1-5 in Iceland

Session Information

• CKD: Risk Scores and Translational Epidemiology
  November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: CKD (Non-Dialysis)

• 2101 CKD (Non-Dialysis): Epidemiology, Risk Factors, and Prevention

Authors

• Jonsson, Arnar Jan, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland

Arnar Jan Jonsson,

• Lund, Sigrún Helga, deCODE genetics, Reykjavík, Iceland

Sigrún Helga Lund,

• Palsson, Runolfur, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland

Runolfur Palsson,

• Indridason, Olafur S., Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland

Olafur S. Indridason,

Background

Studies on survival of patients with chronic kidney disease (CKD) employing the KDIGO definition and classification system with repeated serum creatinine (SCr) and proteinuria measurements are scarce. The purpose of this study was to estimate hazard ratio (HR) for death in patients with CKD stages 1-5 in Iceland.

Methods

In this retrospective study, we obtained all SCr values and urine protein measurements from every clinical laboratory in Iceland in 2008-2016. Clinical information, including ICD-10 diagnosis codes, was retrieved from nationwide electronic medical records. Estimated glomerular filtration rate (eGFR) was calculated from SCr using the CKD-EPI equation. CKD was defined as presence of kidney damage, either ICD-10 diagnosis codes indicating kidney disease or proteinuria, or as eGFR <60 mL/min/1.73 m² for ≥3 months. Cox regression was used for survival analysis with CKD stage as a time-dependent variable and adjustments for age at study entry, sex, number of SCr measurements, initial eGFR, multiple co-morbid conditions and by CKD detection criteria, i.e. proteinuria, kidney specific diagnosis or reduced eGFR, either by a single criterion or various combinations.

Results

We obtained 2,120,232 SCr values for 218,437 individuals and information on proteinuria for 84,364 individuals. A total of 4972 had persistent proteinuria, 5286 had kidney disease diagnoses and 20131 had eGFR <60 mL/min/1.73 m² . The median age was 46 (range, 18-107) years and 47% were men. Compared with individuals without CKD, the hazard ratios (95%CI) for patient survival were 10.39 (7.62-14.17), 3.92 (3.18-4.85), 1.43 (1.31-1.56), 2.00 (1.83-2.20), 3.15 (2.78-3.57) and 11.18 (8.96-13.95) for CKD stages 1, 2, 3a,3b, 4 and 5, respectively.

Conclusion

This nationwide study on survival of patients with CKD, incorporating kidney disease diagnoses and numerous urine protein and SCr values over time, suggests increased risk of death for all CKD stages. While this finding supports current criteria for definition of CKD, a more detailed analysis of the influence age is needed.