To date, the Jaffe method has been used for measuring creatinine in all sample types. From 9th May the Jaffe method will be replaced by an alternative enzymatic method. This change to the enzymatic method is based on national recommendations and considered to be analytically superior, complying with NICE guidelines for both chronic kidney disease and acute kidney injury (https://www.nice.org.uk/guidance/cg182 and https://www.nice.org.uk/guidance/CG169).
Testing by the enzymatic method will also support best coupling to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rate formula recently introduced.
Clinical users should be advised that the method change is accompanied by a reference range change, with revised reference range guidance issued with reports. Please note that where creatinine results are used in comparator calculations (eg, acute kidney injury or estimated glomerular filtration rate) clinicians may notice a soft drift in algorithms and estimations for individual patients.
Serum/plasma
Adults
- Female: 45‑84 µmol/L
- Male: 59‑104 µmol/L
Children
- Up to 2 m: 27‑77 µmol/L; 29‑87 µmol/L Neonates (premature)
- 2‑12 m: 14‑34 µmol/L
- 1‑< 3 y: 15‑31 µmol/L
- 3‑< 5 y: 23‑37 µmol/L
- 5‑< 7 y: 25‑42 µmol/L
- 7‑< 9 y: 30‑47 µmol/L
- 9‑< 11 y: 29‑56 µmol/L
- 11‑< 13 y: 39‑60 µmol/L
- 13‑< 15 y: 40‑68 µmol/L
24‑hour urine
- Female: 6‑13 mmol/24 h (720‑1510 mg/24 h)
- Male: 9‑19 mmol/24 h (980‑2200 mg/24 h)
- Creatinine clearance 66‑143 mL/min