Estimating the surface area of the human body

Area of Science:

• Biometrics
• Medical Physics
• Human Physiology

Background:

• Numerous formulas exist for estimating human body surface area (SA).
• These formulas often share a similar logarithmic functional form but differ in coefficient values.
• Existing formulas' equivalence is demonstrated through the strong linear correlation between log height and log weight.

Purpose of the Study:

• To evaluate existing human body surface area (SA) estimation formulas.
• To establish a recommended standard formula for SA estimation in medical contexts.
• To demonstrate methods for deriving standard errors and confidence intervals for SA estimates.

Main Methods:

• Analysis of the functional form InSA = a(0) + a1lnH + a2lnW.
• Comparison of coefficients across different SA estimation formulas.
• Least squares estimation using a dataset of 401 surface area measurements for the Gehan and George formula.

Main Results:

• All analyzed SA estimation formulas are functionally equivalent due to the strong linear relationship between log height and log weight.
• The Gehan and George formula, derived from 401 measurements using least squares, is recommended as the medical standard.
• Current clinical practice often relies on less accurate formulas based on minimal subject data.

Conclusions:

• The Gehan and George formula provides a robust and statistically sound method for estimating human body surface area (SA).
• Adoption of the Gehan and George formula is advocated to improve accuracy in clinical settings.
• Further analysis allows for the derivation of standard errors and confidence intervals for SA estimates, enhancing clinical utility.