Predictive Equations for Lung Function Based on a Large Occupational Population in North China

Autor: Edgar J. Love, Baoqi Gang, Zhongyi Zhang, Yonghui Wu
Rok vydání: 2009
Předmět:
Zdroj: Journal of Occupational Health. 51:471-477
ISSN: 1348-9585
1341-9145
DOI: 10.1539/joh.l9006
Popis: Predictive Equations for Lung Function Based on a Large Occupational Population in North China: Yonghui WU, et al. Department of Occupational Health, School of Public Health, Harbin Medical University, P.R. China—Objectives: The currently used predictive equations of lung function in North China were derived from early study and have not been updated for nearly two decades. Methods: Using American Thoracic Society (ATS) standards, sex- specific spirometric predictive equations for forced vital capacity (FVC), forced expiratory volume in one second (FEV 1 ), ratio of FEV 1 to FVC (FEV 1 %) and forced expiratory flow at 25-75% of forced vital capacity (FEF 25-75% ) were derived from 2,897 asymptomatic, lifelong non-smokers (1,208 males, 1,689 females) from a large occupational population in North China. Stepwise multiple regressions were carried out to identify the best predictors of lung function parameters and predictive equations. Independent variables considered for inclusion in predictive equations including age, height, weight and chest circumference were examined. Results: Age and height were found to be necessary variables for all lung function parameters. Weight was a significant variable in only half of our equations. Chest circumferences (expired or inspired) was excluded as they are not practical in use. Data from 255 apparently healthy non-smokers were used to validate the equations by comparing percentage predicted values and proportion of subjects with normal predicted values with those from the study group, and a high accordance was obtained. Other equations published and used in North China do not appear to offer advantages over these equations. Conclusions: These newly developed predictive equations should ideally be applied to calculate lung function for adult individuals and populations as reference values in North China. (J Occup Health 2009; 51: 471-477) Spirometry can be a valuable tool and is increasingly used as an objective measure of lung function for a variety of purposes. Due to differences in study populations, techniques or procedures, equations used to predict normal lung function vary 1-3) . It is imperative to establish appropriate predictive equations as reference for a given population. China is a huge country with a vast territory and variety of ethnic groups; thus, it is important to establish predictive equations for lung function parameters applicable to the populations in different geographical regions. Additionally, lung function is estimated by using predictive equations based on studies performed 19 yr ago in relatively small populations 4) . These equations may not be suitable nowadays for predicting lung function. Furthermore, these equations are predominately applied in clinical practice to determine low lung function and focus on respiratory diseases. We have previously indicated that evaluation of respiratory function for an occupational population requires a more strict or sensitive criteria than that for population of patients with respiratory disease because the majority of the employees comprising the former population may experience no or minor impairment of lung function 5) . The aim of this study was to develop predictive equations of lung function based on measurements from a large occupational population in North China with a wide spectrum of age.
Databáze: OpenAIRE
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