Reference Values for the Pulmonary Function of Korean Adults Using the Data of Korea National Health and Nutrition Examination Survey IV (2007-2009)

The objective of this study was to develop new spirometric reference equations for the Korean population using the raw data of the fourth Korea National Health and Nutrition Examination Survey (KNHANES IV, 2007-2009). A total of 4,753 healthy lifelong nonsmokers without respiratory diseases and symptoms were selected as the reference population. Spirometric reference equations were derived through multiple regression analysis. The newly developed reference equations for spirometry parameters were as follows: FEV1 (L) = -0.00025410 x (Age [years])(2) + 0.00012644 x (Height [cm])(2) - 0.00262 x Weight (kg) + 0.61493 (Men); FEV1 (L) = -0.00017538 x Age(2) + 0.00009598 x Height(2) -0.00231 x Weight + 0.46877 (Women); FVC (L) = -0.00000219 x Age(3) + 0.0000006995642 x Height(3) + 1.19135 (Men); FVC (L) = 0.0167 x Age -0.00030284 x Age(2) + 0.0000005850287 x Height(3) + 0.77609 (Women); FEV1/FVC (%) = -0.00289 x Age(2) -0.16158 x Height(3) + 114.13736 (Men); FEV1/FVC (%) = -0.21382 x Age -0.00000143 x Height(3) + 97.62514 (Women). The newly developed spirometric reference equation in this study can be used as criteria for the interpretation of spirometry results and the diagnosis of respiratory diseases in Korean adults.