最低气温对兰州市呼吸系统疾病就诊人次的影响研究

通过2013年1月1日~2017年7月31日兰州市呼吸系统疾病逐日就诊资料和气象资料，采用分布滞后非线性模型（DLNM）方法，分析0~30d滞后影响，研究极端低温对不同年龄（<15岁、16~45岁、46~60岁、>60岁）和性别人群呼吸系统疾病就诊人次的影响.结果发现：日均最低温度对相对危险度（RR）的最大RR变化范围为0.89~1.41，变化趋势整体呈现出V字型，在低温附近，温度越低，RR越高；滞后0~4d，极端低温代表的冷效应影响最为显著；滞后5~19d，在日均最低温度0℃附近，出现新的峰值，冷效应对RR的贡献有所下降，热效应对RR的贡献完全消失；滞后20~30d，日均最低温度为-10℃时，出现RR最小值，0℃温度点附近维持RR峰值；滞后22d时，滞后影响完全消失.在极端低温条件下，呼吸系统疾病对低龄人群表现出长期滞后性和高发性，对高龄人群表现出短期滞后性.男性比女性患病的滞后效应更长，患病风险更大.

Effects of minimumtemperatureonrespiratorydiseasesin Lanzhou

In the current study, we evaluated the effect of extreme low temperature on respiratory diseases in Lanzhou from January 1, 2013 to July 31, 2017 using a distributed lag non-linear model (DLNM) based on the daily data of meteorology and hospital visitsfor respiratory diseases.Age (≤ 15years, 16-45years, 46 -60years, ≥ 60years) and gender (male and female) modification were also performed. Results indicatedthe greatestlag effect of average daily minimum temperature (T_min) on relative risks (RRs)for respiratory diseases. The maximum RR value ranged from 0.89 to 1.41 and the response-effect curvewas V-shaped. At lag of 0~4d, the cold effect represented by extreme low temperature was the most significant. Atlag of 5~19d, a new peak appeared near T_min at 0℃, and the cold effect started to decrease, while the heat effect disappeared completely. At lag of 20~30d, the minimum RR value appeared when T_min was -10℃ and the peak value was near the temperature point of 0℃. Lag effect completely disappearedat 22d. Under extreme low temperatures, respiratory diseases showed long-term hysteresis and higherrisksforthe younger ages, while short-term hysteresis and lowerriskforthe older ages. As to the gender, males showed a longer lag effect than females.