Study On Effects And Prediction Of Diurnal Temperature Range And 24-hour Temperature Change On The Admissions For Circulatory System Diseases

Objective To explore the effects of diurnal temperature range?DTR?,24-hour temperature change?TC24?on the admissions for circulatory system diseases,to preform predictive research of circulatory system diseases based on DTR and TC24,and to provide basic data for prevention of meteorologically susceptible diseases.Methods The outpatient and emergency room?O&ER?visits for circulatory system disease from 3 general hospitals and hospital admissions for circulatory system disease from 4 general hospitals in Jinchang of Gansu Province were collected between January 1,2013 to December 31,2016.Meteorological parameters?including daily average temperature,maximum temperature,minimum temperature,relative humidity,air pressure,and wind speed?and air pollution data(PM₁₀,NO₂,SO₂)were collected during the same study period.?1?Descriptive research methods were used to analyze frequency and time distribution characteristics of O&ER visits and hospital admissions for circulatory system disease,DTR,and TC24.?2?A generalized additive model?GAM?with Poisson regression was employed to analyze the effects of DTR,TC24 on the admissions for circulatory system diseases after controlling long-term trend,day-of-week effect,holiday effect,seasonal effect,meteorological factors,and air pollutants.Stratified analysis was conducted to examine the effects of DTR and TC24 by gender and age.Sensitivity analysis was conducted for non-heating season.?3?Based on the above research results,GAM was also used to preform predictive research of the effects of DTR and TC24 on the O&ER visits for circulatory system diseases.Results 1.The study collected 138367 cases of O&ER visits for circulatory system diseases and an average of 95 daily visits,with 54 cases of hypertension,17cases of ischemic heart disease?IHD?,6 cases of stroke.34699 cases of hospital admissions for circulatory system diseases were collected from 2013-2016 in Jinchang,and an average number of daily visits was 24,with 6 cases for hypertension,6 cases for IHD,4 cases for stroke.The admissions for total circulatory system diseases and three cardiovascular diseases were found obvious season fluctuations,but the long-term trends of the data were different.As a whole,the admissions were on the rise.Meanwhile,there were obvious season fluctuations in DTR and TC24.DTR showed a"hump"change,with peaks in May and October,and the negative and positive TC24 were higher in May and lower in July and August,which were basically consistent with the changes of the cumulative monthly O&ER visits and hospital admissions for circulatory system diseases.However,the simple correlations between DTR,negative TC24,positive TC24 and the admissions for all circulatory system diseases were not statistically significant.2.There were similar positive linear relationship between DTR and the O&ER visits for circulatory system diseases?including total circulatory system diseases,hypertension,IHD and stoke?.DTR had significant lag effects on the O&ER visits for circulatory system diseases that would reach the maximum at cumulative lag 5-7 days,and cumulative lag effects were higher than single lag effects.Generally,a 1?increase of DTR corresponded to 0.22%-1.82%increase in O&ER visits for circulatory system diseases.The effects of DTR on O&ER visits for circulatory system diseases in males and people aged 65 years and older were higher than the effects in female and those of other age groups,and DTR had greater effects in the non-heating season.However,U-shaped relationship was found between DTR and hospital admissions for total circulatory system diseases,hypertension and IHD,and the thresholds were 13.9?,15.4?,and 11.2?,respectively.The effects of DTR on hospital admissions for circulatory system diseases or hypertension were statistically significant when it was more or less than the threshold.When it was less than the threshold,DTR had greater impacts on hospital admissions of males for hypertension and IHD,and had greater impacts on hospital admissions for 65-74year-old total circulatory system diseases an?75 year old hypertension.DTR was positively correlated with hospital admissions for stroke,and the excess risk?ER?was0.83%?0.17%¹.50%?at single lag 6 days.3.U-shaped relationship were found between TC24 and the admissions for circulatory system diseases?including total circulatory system diseases,hypertension,IHD and stoke?.The negative and positive TC24 had significant impacts on the admission for circulatory system diseases.A 1?decrease of negative TC24corresponded to 0.79%-2.12%increase in O&ER visits,and 1.04%-2.23%increase in hospital admissions.A 1?increase of positive TC24 corresponded to 0.92%-3.90%increase in O&ER visits,and 1.95%increase in hospital admissions.The lag effects of negative and positive TC24 reached the maximum at lag 5-6 and 2 days respectively,and the effects of positive TC24 were higher than the effects of negative TC24.The effects of TC24 on the admissions for circulatory system diseases in male and people aged 65 years and older were higher than the effects in female and those of other age groups,and TC24 had greater effects in the non-heating season.4.The range of the fitting accuracy rate of the O&ER visits for circulatory system diseases based on DTR was 64.47%to 82.96%,and the prediction accuracy rate was between 32.69%and 50.15%.The range of fitting accuracy rate of the O&ER visits for circulatory system diseases based on TC24 was 64.45%to 82.81%,and the prediction accuracy rate was between 32.44%and 54.41%.Among the four diseases,the prediction accuracy rate of the O&ER visits for total circulatory system diseases was better,and the prediction accuracy rate of the O&ER visits for stroke was not good base on GAM in this study.Conclusions 1.The admissions for circulatory system diseases,DTR and TC24 have obvious season fluctuations,and their monthly distributions are basically consistent.2.DTR has significant lag effects on the O&ER visits and hospital admissions for circulatory system diseases,but exposure response relationships are different.DTR has positive linear relationships with the O&ER visits,and U-shaped relationships were found for hospital admissions for total circulatory system diseases,hypertension,IHD.3.TC24 has significant effects on the admission for circulatory system diseases,and exposure response relationships are U-shaped.The effects of positive TC24 are higher than the effects of negative TC24.4.The effects of DTR and TC24 on the admissions for circulatory system diseases in males and people aged 65 years and older are higher than the effects in females and those of other age groups.5.Excluding confounding of the heating,DTR and TC24 have greater effects on the admissions for circulatory system diseases in the non-heating season.6.The prediction accuracy rate of the O&ER visits for total circulatory system diseases based on DTR and TC24 was better in this study.