FAS (Full Age Spectrum, 2016)

Adult2016

Lifespan equation covering children to adults

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Calculate FAS

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

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

Formula

For ≤40y:eGFR=107.3Scr/Q; For >40y:eGFR=107.3Scr/Q×0.988age−40\text{For } \leq 40y: \text{eGFR} = \frac{107.3}{S_{cr}/Q}; \text{ For } > 40y: \text{eGFR} = \frac{107.3}{S_{cr}/Q} \times 0.988^{\text{age}-40}

Formula constants

SymbolDescriptionValue
107.3Base coefficient
QQMedian serum creatinine of healthy persons of the same age/sex (Pottel 2016, Table 1)
Female (≥20 y):0.70mg/dL
Male (≥20 y):0.90mg/dL
2–19 y:Age-dependent (see Pottel 2016, Table 1)mg/dL
0.988Age decay factor (age > 40 only)per year
ScrS_{cr}inputSerum creatininemg/dL
AgeinputPatient ageyears

Required inputs

AgeSexCreatinine

Validated age range

2 to 120 years

Limitations

  • Predominantly White European population validation
  • Q values may need adjustment for non-European populations
  • Superseded by the EKFC equation for clinical use
  • Assumes IDMS-standardized (enzymatic) creatinine

Clinical notes

  • Full age spectrum equation (validated ages 2-100)
  • Q = median serum creatinine of age-/sex-matched healthy persons (Pottel 2016, Table 1)
  • Age-dependent Q values used for ages 2-19; constant adult Q from age 20
  • Predominantly validated in White European populations
  • Superseded by the EKFC equation (same research group, 2021)

References

  • [1]Pottel H, et al. An estimated glomerular filtration rate equation for the full age spectrum. Nephrol Dial Transplant. 2016;31(5):798-806. doi:10.1093/ndt/gfv454

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