Association between ambient temperature and cause-specific respiratory outpatient visits: A case-crossover design with a distributed lag nonlinear model in Lanzhou, China

• Published in: Urban climate Vol. 46; p. 101303
• Main Authors: Yang, Renqing, Wang, Yanru, Dong, Jiyuan, Wang, Jiancheng, Zhang, Hong, Bao, Hairong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2022
• Subjects: Ambient temperature; Distributed lag non-linear model; Outpatient visits; Respiratory diseases; Distributed lag non-linear model; RR; RD; Ambient temperature; URTI; Respiratory diseases; Outpatient visits; DLNM; COPD
• ISSN: 2212-0955; 2212-0955
• DOI: 10.1016/j.uclim.2022.101303

Little is known about the association between air temperature and causes-specific respiratory diseases (RD), especially in northwest China. A time-stratified case crossover design with a distributed lag nonlinear model (DLNM) was conducted to assess the nonlinear and delayed effects of temperature on total and cause-specific outpatient visits, with analyses stratified by gender and age. The cumulative effects of temperature were irregular M-shaped curves for total and upper respiratory tract infection (URTI), with inverted U-shaped curve for pneumonia, bronchitis and chronic obstructive pulmonary disease (COPD). Positive cold and heat effects were observed for URTI, pneumonia, bronchitis and COPD, bronchitis was most vulnerable to cold but pneumonia was more affected to heat. Heat effects were immediate whereas cold effects were delayed and lasted longer. The magnitude of temperature effects varies greatly by age, gender, and disease. Notably, the cold effect was greater for children aged 0–14 than that of other age groups. This study suggested that both cold and hot temperatures exposure could increase all-cause and cause-specific respiratory outpatient visits in Lanzhou, China. The harmful effect and duration of cold were greater than that of heat, and children aged 0–14 were more sensitive to cold. Protection against extreme temperatures should be strengthened. •A time-stratified case crossover design with 13 years of respiratory morbidiy data was used to assess temperature effect.•Different lagged effect of temperature on cause-specific respiratory disease exists among different age-group and gender.•The young people were sensitivity to the low temperature.