基于分布滞后非线性模型分析气温对潍坊市手足口病影响

Effect of ambient temperature on hand, foot and mouth disease incidence in Weifang city: a distributed lag non-linear model analysis

目的分析山东省潍坊市手足口病(HFMD)发病的时空特征,探讨气温对潍坊市HFMD发病滞后效应及人群易感性。方法收集2015—2017年潍坊市HFMD发病数据和同期气象数据,进行描述性分析,并建立分布滞后非线性模型(DLNM)分析气温对日HFMD发病状况的定量关系及滞后效应。结果潍坊市2015—2017年HFMD总病例数为18 963例,男女比例为1.58:1;病例多集中于5—7月;气温对HFMD发病有明显的滞后效应,当日均温度达到33℃,滞后天数为6 d时,相对危险度最高(RR=1.76,95%CI=1.26~2.34);以日均温度的P50为参考温度,高温(24℃、29℃)效应较低温(–2℃、4℃)效应显著;5岁以下儿童累积相对危险度高于其他人群。结论气温是潍坊市HFMD发病重要的影响因素,其影响有明显的滞后性;不同温度对不同人群的滞后效应明显不同,高温影响更为显著,5岁以下儿童尤为敏感。

Objective To analyze spatial and temporal distribution characteristics of hand, foot and mouth disease(HFMD) in Weifang city and to explore lag effect of ambient temperature on HFMD and populations vulnerable to the effect.Methods Data on HFMD incidence and meteorological factors from 2015 through 2017 were collected for descriptive statistics. Distributed lag nonlinear model was applied to explore lag effect of ambient temperature on daily HFMD incidence and quantitative relationship between ambient temperature and HFMD incidence. Results During the 3-year period in the city, totally 18 963 HFMD cases were reported and the male to female ratio of the cases was 1.58 : 1, with more cases reported between May and July in a year. An obvious lag effect of ambient temperature on HFMD incidence was observed.The highest relative risk(RR) of 1.76(95% confidence interval: 1.26–2.34) of HFMD incidence was associated with lag 6-day high daily average ambient temperature of 33 ℃. Considering the influence of 50 th percentile daily average ambient temperature as the reference, high daily average ambient temperature(24 ℃/29 ℃) had stronger effect on HFMD incidence than low daily average ambient temperature(– 2 ℃/4 ℃). The cumulative RR of HFMD incidence associated with ambient temperature exposure was higher among children under 5 years old than among other population groups. Conclusion Ambient temperature, with obvious lag effect, is an important influencing factor of HFMD incidence in Weifang city. The lag effect of ambient temperature differs by daily average temperature and in various populations;the effect of high daily average ambient temperature is stronger than that of low temperature and children under 5 years old are more vulnerable to the influence of ambient temperature.