Effectof Temperature Change On The Outpatient Visits For Acute Bronchitis In Children:a Time-series Study In Hefei,China

Objectives:1.To better understand the incidence characteristic of childhood acute bronchitis in Hefei.2.Use the time-series analysis method to explore the relationship between between temperature and the outpatient visits for acute bronchitis in children,and to identify vulnerable group,so as to provide theoretical foundation for improving the effect of acute bronchitis prevention and control.Methods:1.Data on daily counts of AB among children aged 0-14 yearsfrom 1st June 2010 to 31 st July 2013 were obtained from Anhui Province Children's hospital.The data including gender,age,address,date of onset and diagnostic code.Daily meteorological data including maximum,minimum,and mean temperature and relative humidity were collected from Hefei Meteorological Bureau.2.Poisson generalized linear regression model combined with distributed lag non-linear model was used to analyze the association between temperature change(mean temperature and diurnal temperature range)and hospital visits for acute bronchitis.3.We performed the stratified analyses by gender and age group(0-4 years and 5-14 years),which could help in the provision of timely interventions for the target population.Results:1.We observed a significant seasonality for childhood acute bronchitis during 2010-2013 in Hefei and the peak is in winter.2.There were 14,055 cases of AB among children aged 0-14 years in Hefei across the whole study period.The average number of daily childhood acute bronchitis cases was 51.9(range: 0-115).There were moremale cases with a male-to-female sex ratio of 2.4:1(9918:4137).The average values of mean temperature,Maximum temperature,Minimum temperature,and relative humidity were 3.9?(range:-2.8?~15.3?),8.2?(range:-1.1?~22.3?),0.4?(range:-8.0?~11.0?)and 69.5%(range:22.0%~100%)respectively.3.There was a non-linear link between temperature and childhood acute bronchitis,and temperature effect appeared to be acute.Temperature drop could increase the risk of childhood acute bronchitis,and the impact of mean temperature was greatest in the current day,with 1.6%(95% confidence interval = 0.3-7.6%).Female children and children aged 0-4 years appeared to be more vulnerable to mean temperature effect than other children.4.An adverse effect of diurnal temperature range(DTR)on childhood acute bronchitis was observed,and the impact of DTR was greatest at three days lag,with a 1.0%(95% confidence interval = 0.5-1.6%)increase of childhood acute bronchitis cases per 1 ? increment of DTR.Female children and children aged 0-4 years appeared to be more vulnerable to DTR effect than other children.Conclusions: 1.Childhood acute bronchitis had an apparent seasonal trend,peaking during winter.2.Low temperature can increase the risk of childhood acute bronchitis.Female children and children aged 0-4 years appeared to be more vulnerable to mean temperature effect than other children.3.An adverse effect of DTR on childhood acute bronchitis was observed.We also found female children and children aged 0-4 years appeared to be more vulnerable to DTR effect than other children.