CKiD U25 Creatinine-Cystatin C

Pediatric2021Recommended

Age 1-25 years combined biomarker equation - most accurate

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Calculate CKiD U25 Cr-Cys

Enter the values required by this equation to estimate the result.

Enter all required values to see the result.

For educational and clinical reference use. Interpret results in clinical context.

Formula

eGFR=eGFRcr+eGFRcys2\text{eGFR} = \frac{\text{eGFR}_{\text{cr}} + \text{eGFR}_{\text{cys}}}{2}

Formula constants

SymbolDescriptionValue
eGFRcr\text{eGFR}_{\text{cr}}CKiD U25 Creatinine result (see CKiD U25 Creatinine equation)mL/min/1.73m²
eGFRcys\text{eGFR}_{\text{cys}}CKiD U25 Cystatin C result (see CKiD U25 Cystatin C equation)mL/min/1.73m²

Required inputs

AgeSexHeightCreatinineCystatin C

Validated age range

1 to 25 years

Limitations

  • Requires both creatinine and cystatin C measurements
  • Higher cost than single-biomarker equations
  • Requires accurate height measurement for creatinine component

Clinical notes

  • Most accurate pediatric eGFR equation available
  • Averages creatinine and cystatin C estimates
  • Preferred when both biomarkers are available
  • Superior accuracy and precision compared to single-marker equations

References

  • [1]Pierce CB, Muñoz A, Ng DK, Warady BA, Furth SL, Schwartz GJ. Age- and sex-dependent clinical equations to estimate glomerular filtration rates in children and young adults with chronic kidney disease. Kidney Int. 2021;99(4):948-956. doi:10.1016/j.kint.2020.10.047
  • [2]Ng DK, Pierce CB. Kidney disease progression in children and young adults with pediatric CKD: Epidemiologic perspectives and clinical applications. Semin Nephrol. 2021;41(5):405-415. doi:10.1016/j.semnephrol.2021.09.002

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