Study On The Influence Of Air Pollutants On Outpatient Visits Of Cardio-cerebrovascular Diseases In Henan Province

Air pollutants are one of the main factors of global disease burden,and cardio-cerebrovascular disease is a major public health problem that threatens global public health.At present,the research on the impact of air pollutants on cardio-cerebrovascular diseases has become a global research hotspot.The existing studies mainly explore the effects of air pollutants on cardio-cerebrovascular diseases through time series or pathological research methods,and pay less attention to the spatial characteristics of air pollutants and cardio-cerebrovascular diseases.Therefore,to explore the spatio-temporal evolution characteristics of cardio-cerebrovascular diseases and analyse the spatial heterogeneity of the effects of air pollutants on cardio-cerebrovascular diseases combined with spatial regression models,it is helpful for public health management departments to formulate regional measures for the prevention and control of cardio-cerebrovascular diseases to provide reference and guidance.Henan Province is one of the provinces with the largest number of patients with cardio-cerebrovascular diseases in China,so this study takes the outpatient data of cardio-cerebrovascular diseases in Henan Province as the original data.On this basis,using geographic information technology and related spatio-temporal analysis methods,three spatial regression models of least square regression(OLS),geographically weighted regression(GWR)and multi-scale geographically weighted regression(MGWR)were established,and the spatio-temporal evolution characteristics of outpatient visits of cardio-cerebrovascular diseases in Henan Province from 2016 to 2018 were fully discussed.The effects of seven kinds of air pollutants(PM1,PM2.5,PM10,SO2,NO2,CO,O3)on outpatient visits of cardio-cerebrovascular diseases in Henan Province were analyzed at the county scale.The main results of this paper are as follows:(1)Based on the statistics and analysis of the outpatient data of cardio-cerebrovascular diseases in Henan Province from 2016 to 2018,it was found that the number of outpatients of cardio-cerebrovascular diseases in Henan Province was increasing year by year,in which the number of cardio-cerebrovascular diseases in males was higher than that in females.And about 90%of the patients were middle-aged and elderly people over 50 years old.The time periods with more outpatients of cardio-cerebrovascular diseases in each year were mainly concentrated in February-May and October-December of each year.There was a significant spatial autocorrelation in the spatial distribution of cardio-cerebrovascular diseases.The high incidence areas of outpatients were mainly distributed in central and western Henan,and transfer and spread to the southwest and southeast year by year.(2)Based on correlation,significance,and Multicollinearity test results,in the collected meteorological data,socio-economic and resource data,physical and environmental characteristics of the data screened out the resident population,temperature,evapotranspiration,topography(DEM)and the number of hospitals as co-variables,based on the OLS,GWR and MGWR models,the spatial regression models of the effects of pollutants on cerebrovascular disease were constructed.Based on the processed and screened air pollutant data and auxiliary impact data,the spatial regression models of the effects of various pollutants on the outpatient volume of cardio-cerebrovascular diseases were established based on OLS,GWR and MGWR models.At the same time,according to the regression parameters of the three models,the sum of squares of residuals(RSS),corrected Akaike information criterion(AICc)and the corrected decision coefficient(Adj.R2)were used as indicators to evaluate the advantages and disadvantages of each model.The results showed that the fitting effect of MGWR model was better than that of OLS and GWR model,which can reflect the difference of the impact of air pollutants on the outpatient visits of cardio-cerebrovascular diseases on the county scale more succinctly and more accurately.(3)The regression coefficients of each pollutant in MGWR model were visualized on the map by geographic information technology.On the whole,SO2 and PM1 were the pollutants with the greatest influence on outpatient visits of cardio-cerebrovascular diseases in Henan Province from 2016 to 2018.On the county scale,there were significant regional differences in the impact of seven pollutants on outpatient visits of cardio-cerebrovascular diseases,and the affected areas were decreasing year by year.In 2016,the areas most affected by pollutants were distributed in the whole Henan Province except Hebi City,Anyang City and Puyang City.In 2017,the areas heavily affected by pollutants were mainly distributed in Jiyuan City,Jiaozuo City,Zhengzhou City,West Henan and South Henan.In 2018,the areas heavily affected by pollutants were mainly distributed in and around Xinyang City.