Predictive Equations Using Regression Analysis of Pulmonary Function for Healthy Children in Northeast China

Abstract

BackgroundThere have been few published studies on spirometric reference values for healthy children in China. We hypothesize that there would have been changes in lung function that would not have been precisely predicted by the existing spirometric reference equations. The objective of the study was to develop more accurate predictive equations for spirometric reference values for children aged 9 to 15 years in Northeast China.Methodology/Principal FindingsSpirometric measurements were obtained from 3,922 children, including 1,974 boys and 1,948 girls, who were randomly selected from five cities of Liaoning province, Northeast China, using the ATS (American Thoracic Society) and ERS (European Respiratory Society) standards. The data was then randomly split into a training subset containing 2078 cases and a validation subset containing 1844 cases. Predictive equations used multiple linear regression techniques with three predictor variables: height, age and weight. Model goodness of fit was examined using the coefficient of determination or the R2 and adjusted R2. The predicted values were compared with those obtained from the existing spirometric reference equations. The results showed the prediction equations using linear regression analysis performed well for most spirometric parameters. Paired t-tests were used to compare the predicted values obtained from the developed and existing spirometric reference equations based on the validation subset. The t-test for males was not statistically significant (p>0.01). The predictive accuracy of the developed equations was higher than the existing equations and the predictive ability of the model was also validated.Conclusion/SignificanceWe developed prediction equations using linear regression analysis of spirometric parameters for children aged 9–15 years in Northeast China. These equations represent the first attempt at predicting lung function for Chinese children following the ATS/ERS Task Force 2005 guidelines on spirometry standardization.

Peak expiratory flow among healthy children aged 5–14 years in China

“…In addition, environmental factors affecting growth and development, such as child health nutritional status and air quality, may change over long periods (26); therefore, PEF values for a given ethnic community may change over time. To the best of our knowledge, there are only seven studies in the literature that used predictive equations for PEF in Chinese children (3)(4)(5)(6)(7)(8)(9)(10); however, these studies were all geographically specific. Although no differences were found between different areas of China, the results of these studies are unlikely to be representative and generalizable to the entire population of children in China (6).…”

“…However, normal PEF values for Chinese children have not been thoroughly investigated. To date, there have been only a few studies on normal PEF values, all of which have been geographically specific (3)(4)(5)(6)(7)(8)(9)(10). These are therefore unlikely to be representative and generalizable to the entire population of Chinese children.…”

Effects of in utero and Postnatal Exposure to Secondhand Smoke on Lung Function by Gender and Asthma Status: The Seven Northeastern Cities (SNEC) Study

“…Decreased lung function was defined as FEV 1 % <85% or FVC <85%, or PEF <75%, or MMEF <75% of the predicted value of the respective parameter [20] . These 4 outcomes were analyzed dichotomously as decreased or normal.…”

Reference values for spirometry in Chinese aged 4–80 years

“…Although several spirometric reference values for Chinese have been published (13)(14)(15)(16)(17)(18)(19)(20)(21)(22), the major disadvantages in these studies limited the nationwide use, including small samples, limited age ranges, small local regions, as well as different study protocols and quality control. Without LLNs for nationwide Chinese, a fixed 0.7 of forced expiratory volume in 1 second to forced vital capacity (FEV 1 /FVC) instead of LLNs was frequently applied for the diagnosis of "airflow limitation" in previous studies (7,23,24), leading possible underdiagnosis in younger subjects and over diagnosis in elderly.…”