[Comparison between predicted equations obtained by standard Japanese values and present predicted equations for vital capacity and forced expiratory volume in one second].

Until recently, predicted values of vital capacity (VC) and forced expiratory volume in one second (FEV1) have been calculated with Baldwin's equation (VC-B) and Berglund's equation (FEV1-B) respectively, in Japan. Due to several problems using these equations, new prediction equations of VC (VC-J) and FEV1 (FEV1-J), which were created using data from healthy Japanese, were provided by the Japanese Respiratory Society in 2001. In the present study, we studied the validity of these prediction equations.