Combined Model Analysis On Three Reference Values Of Pulmonary Ventilation Function And Geographical Environment

Respiratory disease is the common and frequently-occurring disease, and also a top-ranking disease in the prevalence of short-term, chronic disease hospitalization rates and mortality of the main diseases."Chinese Health Statistics Yearbook2012" shows that respiratory diseases accounted for four kinds of the prevalence of top ten diseases in urban and rural residents; while also ranked fourth in the ten previous disease mortality, reaching10.56%in caused inpatient death. Pulmonary ventilation function tests play an irreplaceable role in the diagnosis, treatment and prevention of respiratory diseases. Regional adaptation is one of most important characteristics in lung function reference values. But little study on relationship between various geographical factors and reference values for pulmonary function by quantitative method.Through literature search and survey methods, three reference values (Forced expiratory flow after25%of the FVC has been exhaled, forced expiratory flow after50%of the FVC has been exhaled, forced expiratory flow after75%of the FVC has been exhaled) of pulmonary ventilation function has been collected in China according to classification of sex, age, sample size, equipment, city (county). According to the characteristics of the terrain and climate in China, space index selected longitude (X1), latitude (X2), terrain index selected altitude (X3), climate index for annual sunshine hours (X4), annual average temperature (X5), annual average relative humidity (X6), annual precipitation (X7), annual range of temperature (X8), annual average wind speed (X9) as indicators of geographical factors. Based on cross-sectional data, qualitative described general rules of three reference values of pulmonary ventilation function by the method of tabular data comparing, trend surface analysis and exploring mapping. Through correlation analysis, regression analysis, curve estimation, combination modeling and geostatistical mapping methods, quantitative analysis three reference values of pulmonary ventilation function and geographical factors. Finally, verified the consistency of results between qualitative analysis and quantitative analysis, and summarized the spatial distribution of three reference values of pulmonary ventilation function.After above analysis, there is significant correlation among annual sunshine hours, annual average relative humidity and annual precipitation and three reference values of pulmonary ventilation function in old boys ’and old girls’ group; In adolescent group, three reference values of pulmonary ventilation function shows significant correlation with longitude, altitude, annual relative humidity, annual precipitation, annual temperature and annual average wind speed; In young group, significant correlation can be found in altitude, annual temperature, annual range of temperature, annual average wind speed, annual sunshine hours with three reference values of pulmonary ventilation function; In presenile-old group, only female’s three reference values of pulmonary ventilation function significant affected by longitude, annual sunshine duration, average annual temperature and wind speed. By the method of linear regression model, nonlinear of curve estimation model and combination model,21prediction models for FEF25%, FEF50%and FEF75%reference value have been established in different age groups, different gender of healthy Chinese based on geographical factors, the model has highly fit. There is same spatial distribution between exploring map and geo-statistical map.19spatial distribution maps clearly show the spatial variation of the FEF25%, FEF50%and FEF75%reference values. Ultimately, there is a high degree of consistency between the results of qualitative analysis and quantitative analysis.Above all, following conclusion can be summarized:(1) There is a significant relationship between the three reference values of pulmonary ventilation function and geographical factors. With age increase,"U" shaped variation was showed in correlation among FEF25%, FEF50%and FEF75%and geographical factors, which is higher in the elderly group and children group, and lower in youth group. On gender differences, female’s FEF25%, FEF50%and FEF75%reference value is more susceptible to the influence of geographical factors than the reference value of male’s one. According to correlation of the three reference value and geographical factors from strong to weak order:FEF25%>FEF50%>FEF75%.(2) Establishment21predicted models of three reference values of pulmonary ventilation function in healthy Chinese based on geography show that the nonlinear relationship between prediction models should be the optimal choice. In nonlinear models, quadratic function, cubic function and countdown function model is most appeared. These result explained that the relationship between geographic factors and FEF25%, FEF50%and FEF75%reference value is diverse, non-global monotonic.(3)The distribution map of three reference values on pulmonary ventilation function in healthy Chinese successful shows its visual renderings. It is suitable to discover the rules of space, and also facilitate the clinical medical workers to directly read local reference from the map.