1 - Scheme Overview

This External Quality Assessment scheme assesses the accuracy of quantitative methods for serum and urine creatinine and cystatin. It also allowes to evaluate the differents clearance calculations (with the exception of the MDRD formula).

Participating labs can choose to be assessed for all the analytes of this scheme, or simply a subset of analytes of interest.

2 - Assessment Frequency

Number of surveys per year: 5
Number of control samples per survey: 2 (1 serum sample and 1 urine sample) or 4 (2 serum samples and 2 urine samples)
Number of samples per year: 14 (6 urines and 6 serums lyophilised + 1 fresh urine and 1 fresh serum)

3 - List of Analytes Assessed 

• Serum creatinine
• Urinary creatinine
• Mesured Creatinine clearance
• COCKROFT
• CKD-EPI
• EKFC
• Cystatin C

4 - Description of the Control Samples

6 serums and 6 urines, control of human origin and lyophilised (samples to be resuspended in 1 mL of distilled water).

1 fresh serum and 1 fresh urine, control of human origin (ready-to-use, 0.5 mL of serum and 1.5 mL of urine)

5 - Demographic Data

The patient’s demographic data (sex, ethnic origin, weight, age) and diuresis rate are provided in the technical notes of the scheme.