Screening Of Regional Temperature Sensitive Diseases And Assessing Of Attributable Outpatient Burden

Backgrounds:Climate change affects human health and increases the risk of mortality and morbidity.Numerous studies have analyzed the relationship between ambient temperature and human health,which mainly focus on death and the research on the impact of temperature on non-fatal events is lacking.Objectives:To analyze the relationship between temperature and outpatients in 18 districts/counties of China,so as to estimate the effect of extreme temperatures on outpatients in different regions of China,and to identify extreme temperatures sensitive diseases in different regions of China.According to age and sex stratification analysis,the influence of temperature on outpatients of different sex and age groups was analyzed to identify the vulnerable population.To assesse the burden of extreme temperature-sensitive diseases and vulnerable populations attributed to non-optimal temperatures.Materials and methods:Daily meteorological data,daily pollutant data and daily outpatient visits data in 18 cities or counties of China during 2014-2018 were collected.Firstly,the distributed lag nonlinear model(DLNM)was used to fit the exposure response relationship between temperature and daily outpatient visits in each study city or county.A multivariate meta-regression analysis was then used to pool the estimation of each city or county to analyze the effect of extreme temperatures on the daily outpatient visits by etiology,sex and age,so as to identify extreme temperatures sensitive diseases and vulnerable populations.After dividing the study area into temperate monsoon climate and subtropical monsoon climate,the regional differences were further estimated and the attributable fractions(AFs)were calculated by diseases,sex,age and regions to evaluate the risks attributed to both hot and cold temperatures.Results:1.Extreme high temperature sensitive diseasesExtreme high temperature increased the outpatient risk of the total population,and the cumulative relative risk(CRR)was 1.095(95%CI:1.021,1.175).Extreme high temperature sensitive diseases included:respiratory system,digestive system,endocrine system,genitourinary system diseases,injury and skin diseases,with CRR of 1.254(95%CI:1.037,1.515),1.128(95%CI:1.024,1.244),1.103(95%CI:1.029,1.393),1.058(95%CI:1.002,1.119),1.313(95%CI:1.063,1.621),and 1.221(95%CI:1.044,1.426),respectively.Enteritis and urolithiasis were sensitive to extreme heat,with CRR of 1.518(95%CI:1.195,1.929)and 1.373(95%CI:1.014,1.858),respectively.For total outpatient visits,the extreme high temperature increased outpatient risk in temperate monsoon climate regions while the effects of extreme high temperature on subtropical monsoon climate regions were not statistically significant.For subtropical monsoon climate areas,extreme high temperature sensitive diseases included enteritis,thyroid disease,urolithiasis and skin disease.For temperature monsoon climate areas,extreme high temperature sensitive diseases included respiratory system,acute upper respiratory tract infection,influenza and pneumonia,digestive system and genitourinary system.2.Extreme low temperature sensitive diseasesExtreme low temperature increased the outpatient risk of acute upper respiratory tract infection and enteritis,with CRR of 1.276(95%CI:1.065,1.528)and 1.048(95%CI:1.011,2.166),respectively.The effects of extreme cold on total outpatient in subtropical and temperate monsoon climates areas were not statistically significant.3.Vulnerable populationIn sex and age stratification analyses,men were more vulnerable to extreme heat than women,with CRR of 1.120(95%CI:1.015,1.236)and 1.075(95%CI:1.032,1.163),respectively.The age groups sensitive to extreme heat were people aged 7～17,18～44 and 60～74 year-old,with CRR of 1.281(95%CI:1.033,1.588),1.119(95%CI:1.033,1.212)and 1.089(95%CI:1.007,1.178),respectively.No significant effects of extreme low temperatures were found.4.Attributable morbidity burdenAFs value of high temperature and low temperature were 3.613%and 0.842%,respectively.As for extreme high temperature sensitive diseases,moderate hot contributed to the largest attributable fraction.Among them,the attributable burden of urolithiasis was the largest with AF of 7.204%,followed by skin disease 3.954%,enteritis 3.777%,genitourinary system 3.215%,respiratory system 3.132%,injury 3.057%and digestive system 2.631%.For extreme hot,the morbidity burden of urolithiasis was the largest,followed by genitourinary,skin disease,injury,respiratory system diseases,enteritis and digestive system diseases.As for Extreme cold sensitive diseases,moderate cold contributed to the largest attributable fraction.For moderate cold,the morbidity burden of acute upper respiratory tract infection was the largest,followed by enteritis disease.For extreme cold,the morbidity burden of acute upper respiratory tract infection was the largest,followed by enteritis disease.The attributable burden of high temperature was greater than that of low temperature.Besides,it was found that male had a greater morbidity burden than female.For different age groups,the morbidity burden of aged 7～17 year-old was the largest,followed by 18～44,60～74 and 0～6 age groups.For different climatic zones,the outpatient burden due to high temperature in temperate monsoon climate areas accounted for 4.533%of the total outpatient,which was higher than that in subtropical monsoon climate areas.The outpatient burden due to low temperature in temperate monsoon climate areas accounted for 1.262%of the total outpatient,which was higher than 0.408%in subtropical monsoon climate areas.Conclusions:Extreme temperatures increased the risk of outpatients.Extreme high temperature sensitive diseases included respiratory system,digestive system,endocrine system,genitourinary system diseases,injury,skin disease,acute upper respiratory tract infection,enteritis and urolithiasis.Extreme cold temperature sensitive diseases included acute upper respiratory infections and enteritis.Extreme high temperature had a greater impact on temperate monsoon climate areas.The attributable burden of male was higher than that of female,and adolescents aged 7～17 years were the most sensitive population.