Use of statistical methods to estimate body composition.

Epidemiologic investigations of chronic diseases in relation to body composition require large samples. This necessitates simple, reliable, and portable measures of body composition. Bioelectrical impedance analysis (BIA) variables and selected anthropometric characteristics are frequently used to predict body composition for groups or individuals when the application of sophisticated methods is not practical. We address statistical issues pertinent to the formulation of prediction equations for body composition from BIA measures and anthropometry, and factors associated with the accuracy and precision of the prediction equations.