The established Cole-Cole and newer Siconolfi methods for analysis
of multifrequency impedance data were compared in a group of
normal healthy individuals studied under bedside conditions.
Impedance quotients derived from each procedure were similarly
well correlated with independent dilutional estimates of total
body water. Although both methods estimated resistance at zero
frequency, were highly correlated, and provided impedance quotients
with very similar correlations with extracellular water, these
estimates were significantly different and thus may not be used
interchangeably. The Siconolfi procedure demonstrated no significant
advantage over the Cole-Cole method. In view of the sound theoretical
basis for the latter, it is concluded that analysis of MFBIA
data by the Cole-Cole method is to be preferred.
