Association of temperature variability with the risk of initial outpatient visits for allergic rhinitis: a time-series study in Changchun

Epidemiological studies have revealed associations between several temperature parameters and allergic rhinitis (AR). However, few studies have reported the association of AR with daily temperature variability, which indicates both short-term intra- and interday temperature changes. This study aimed to analyze associations between temperature variability and initial outpatient visits for AR. The analysis was conducted with an over-dispersed Poisson model using daily time-series data on temperature and the number of initial AR outpatients from 2013 to 2015 in Changchun, China. The composite index of temperature variability was derived by calculating the standard deviation of daily minimum temperature and maximum temperature over exposure days. Stratified analysis by season was also conducted. There were 23,344 AR outpatients during the study period. In the total period, per 1 °C increase in temperature variability at 0-2 days (TV0-2), 0-3 days (TV0-3), and 0-4 days (TV0-4) was associated with a 4.03% (95% CI: 0.91-7.25%), 4.40% (95% CI: 0.95-7.97%), and 4.12% (95% CI: 0.38-8.01%) increase in the number of AR outpatients, respectively. When stratified by season, the strongest effect was shown in spring. Our results suggested that temperature variability was associated with increased initial outpatient visits for AR, which may provide helpful implications for formulating public health policies to reduce adverse health impacts of unstable temperature.