Normative values of pulmonary function testing in Chinese adults

Objectives To compare the difference in pulmonary function between Caucasians and Chinese and assess the best reference values of pulmonary function for Chinese adults. Methods Values for pulmonary function were predicted by tests on 4773 Chinese healthy subjects (male: 2560, female: 2213, aged 15 - 78 years) in six parts (north, northeast, northwest, east, southwest and south) of China. Prediction equations of the European Community for Steel and Coal ( ECSC), other equations for overseas Chinese or for Caucasians were also selected. The regression coefficients of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, total lung capacity (TLC) and residual volume (RV) were summarized. Results ECSC predictions were closer to the Chinese ones than other selected equations. Comparison with ECSC predictions showed that on average the values for FVC, FEV1 were 5.3% smaller in Chinese males and 3.3% smaller in Chinese females, with the maximal differences in south China and the minimal differences in North China. RV and TLC in Chinese were lower than in Caucasians (males 4.8%, 5.5%, respectively; females 8.7% and 6.0%, respectively). Conversion factors were given for adjusting ECSC equations to fit Chinese. Conclusions For predicting values of pulmonary function in Chinese, we suggest to use the equations reported here. Alternatively, ECSC regression equations may be used with appropriate conversion factors.