Table 1 Inclusion and exclusion criteria

Inclusion criteria

1. Age of 18-80 years

2. Capable of understanding the purpose and risks of the study, to be fully informed and to give informed consent

3. Either

- eGFR < 30 ml/min/1.73m² but not on dialysis or with a kidney transplant

- Haemodialysis or peritoneal dialysis

- Kidney transplant recipient at least 6 weeks after transplantation

Exclusion criteria (≥ 1)

•Patients who opted out for the national dialysis (RENINE) and kidney transplantation (NOTR) registries.