Table 3.

Comparison between the modified Thomas formula and the Calvert formula based on Cockcroft-Gault equation for all, obese, normal weight, and underweight patients

Patientsmape (%)*
mpe (%)
5th percentile (%)
95th percentile (%)
% of patients with absolute percent error > 20%
ThomasCalvertThomasCalvertThomasCalvertThomasCalvertThomasCalvert
All (n = 357)1517+1−6−25−3233332538
Obese (n = 43)1214−3+1−28−3025282330
Normal weight (n = 285)1518+1−7−24−3136332539
Underweight (n = 29)1521−2−11−33−4228232845
  • * Mean absolute percentage error as a measure of precision.

  • Mean percentage error as a measure of bias.