Body surface area estimation: Cross validation of several prediction equations

Background Body surface area (BSA) is used in
clinical practice to prescribe medication, standardize
measured parameters etc. Normogram has been the
gold standard. However, there are several prediction
equations in the published literature. A simple
method giving an accurate estimation would help to
assess BSA in day to day clinical practice efficiently.
Objective To assess the accuracy of different
equations for the estimation of BSA in a group of Sri
Lankan children.
Method Data collected in 3 different school surveys
carried out between 2002 and 2005 were used. BSA
estimated by 9 prediction equations described in the
literature were compared with the BSA assessed by
normogram.
Results Two thousand three hundred and thirty eight
girls and 639 boys, between the ages of 5-16 years,
were assessed. The mean ages of the boys and girls
were 10.3±1.47 years and 11.5±2.47 years
respectively. The highest mean BSA estimation was
given by Gehan & George equation (boys
1.14±0.20m2 and girls 1.2 ± 0.25m2) and lowest by
Yu et al (boys 1.08±0.20m2 and girls 1.13±0.25m2).
Estimates correlated highly with BSA assessed by
normogram. When the estimates were compared with
normogram, equation of Mattar gave the highest bias
for both groups (females 0.0152m2 and males
0.0177m2). Mosteller equation gave relatively low
bias (females 0.0077m2, and males 0.0072 m2).
Conclusions All equations gave very good agreement
between each other. Out of the equations, easiest to
use in day to day clinical practice is the equation
described by Mosteller. The maximum bias in
estimation would lead to less than 5% error in
determining drug doses which is negligible in day to
day clinical practice. Mosteller equation is suitable
for routine clinical use.

Sri Lanka Journal of Child Health, 2009; 38: 54-59

(Key words: Body surface area, Sri Lankan children, Mosteller equation, Boyd-West normogram)

doi: 10.4038/sljch.v38i2.679