Effects of Temperature on Outpatient Visits for Urticaria among Lanzhou Residents Based on Distributed Lag Non-linear Model / 中国医学科学院学报

Objective To evaluate the influence of temperature on the outpatient visits for urticaria in Lanzhou City and its hysteresis and to find out the sensitive populations by sex and age stratification.Methods We collected the urticaria outpatient data in three grade A class three hospitals as well as the meteorological data and air pollutant data in Lanzhou from January 2011 to December 2017.The distributed lag non-linear model(DLNM)was employed to analyze the influence of daily mean temperature on the outpatient visits for urticaria.Stratification analysis was performed for different age groups(0-14,15-59,≥60 years)and different sex populations.Results Temperature had a non-linear relationship with the outpatient visits for urticaria,and there existed hysteresis.During the research period,the average daily outpatient visits for urticaria at the three hospitals in Lanzhou was 25,ranging from 1 to 76.With the rise in the daily mean temperature within 0-10 ℃,the risk of outpatient visits for urticaria first increased and then decreased.When the daily mean temperature was 2 ℃,hysteresis occurred on the 18th day,and the relative risk(

Effects of daily average temperature on the daily number of outpatient visits for eczema in two third-grade class-A hospitals in Lanzhou city / 中华皮肤科杂志

Objective To evaluate effects of the daily average temperature on the daily number of outpatient visits for eczema in Lanzhou city.Methods Clinical data were obtained from outpatients with eczema in the Department of Dermatology of 2 third-grade class-A hospitals in Lanzhou city from January 1st 2007 to December 31st 2015,and meteorological data during this period were also collected.Controlling for confounding factors like long-term trends and day of the week,a distributed lag non-linear model (DLNM) fitted with quasi-Poisson link function was used to assess the effects of daily average temperature on the daily number of outpatient visits for eczema,and the analysis was stratified by season,age and gender.Results The exposure-response relationship between the daily average temperature and daily number of outpatient visits for eczema could be roughly described by a W-shaped curve.Stratification analysis showed that the effect of the daily average temperature on outpatient visits for eczema was strongest in autumn and winter,followed by summer,and weakest in spring.Low temperature may have lagged,cumulative and persistent effects on the daily number of outpatient visits for eczema,with the maximum relative risk (RR) value (1.12 [95％ CI:1.03-1.22]) observed at-9 ℃ on lag day 14.With a 1 ℃decrease in the temperature,16％ (RR =1.16,95％ CI:1.00-1.03),14％ (RR =1.14,95％ CI:1.02-1.26) and 13％ (RR =1.13,95％ CI:1.02-1.25) increases in the daily number of outpatient visits for eczema were observed in men,teenagers and middle-aged adults respectively (P ＜ 0.05).However,low temperature had no significant effects on outpatient visits for eczema among women or the elderly (P ＞0.05).The effect of high temperature usually occurred following exposure without lag periods,and was gradually weakened over lag time (P ＞ 0.05).Conclusions In Lanzhou,the effect of daily average temperature on outpatient visits for eczema was strongest in autumn and winter.Changes of the daily temperature may be one of risk factors for eczema.Low temperature had lagged effects on the daily number of outpatient visits for eczema,and the effects were strongest on lag day 14.