New formula for the prediction of risidual volume in females

Abstract

The purpose of this investigation was to develop a new prediction equation for residual volume (RV) in females, based on measurements using the closed circuit, oxygen dilution method. A sample population of 124 females, from 10 to 82 years of age, was selected so that there were 20 subjects (Ss) in each age decade. The physical characteristics of age, height (Ht), weight (Wt), smoking history (Sm), vital capacity (VC), and forced expiratory volume per second (FEV-1) were measured and subjected to stepwise regression analysis, resulting in the prediction equation: RV (liters) = .029 Age + .025 Ht - .011 Wt + .013 Sm - 2.689. The standard error of estimation (S.E.E.) of this equation (332 mls) compared favorably with previous equations for predicting RV in females reported by Crapo et al. (S.E.E. = 381 mls), Goldman and Becklake (S.E.E. = 360 mls), and Grimby and Soderholm. However, using the physical characteristics of the subjects from the present study, each of the previously published equations gave predicted RVs that were significantly (p < .05) different from both the actual predicted RVs and the RVs predicted by the new equation.