RT Journal Article
SR Electronic
T1 Seasonal temperature variability and emergency hospital admissions for respiratory diseases: a population-based cohort study
JF Thorax
JO Thorax
FD BMJ Publishing Group Ltd and British Thoracic Society
SP 951
OP 958
DO 10.1136/thoraxjnl-2017-211333
VO 73
IS 10
A1 Shengzhi Sun
A1 Francine Laden
A1 Jaime E Hart
A1 Hong Qiu
A1 Yan Wang
A1 Chit Ming Wong
A1 Ruby Siu-yin Lee
A1 Linwei Tian
YR 2018
UL http://thorax.bmj.com/content/73/10/951.abstract
AB Background Climate change increases global mean temperature and changes short-term (eg, diurnal) and long-term (eg, intraseasonal) temperature variability. Numerous studies have shown that mean temperature and short-term temperature variability are both associated with increased respiratory morbidity or mortality. However, data on the impact of long-term temperature variability are sparse.Objective We aimed to assess the association of intraseasonal temperature variability with respiratory disease hospitalisations among elders.Methods We ascertained the first occurrence of emergency hospital admissions for respiratory diseases in a prospective Chinese elderly cohort of 66 820 older people (≥65 years) with 10–13 years of follow-up. We used an ordinary kriging method based on 22 weather monitoring stations in Hong Kong to spatially interpolate daily ambient temperature for each participant’s residential address. Seasonal temperature variability was defined as the SD of daily mean summer (June–August) or winter (December–February) temperatures. We applied Cox proportional hazards regression with time-varying exposure of seasonal temperature variability to respiratory admissions.Results During the follow-up time, we ascertained 12 689 cases of incident respiratory diseases, of which 6672 were pneumonia and 3075 were COPD. The HRs per 1°C increase in wintertime temperature variability were 1.20 (95% CI 1.08 to 1.32), 1.15 (1.01 to 1.31) and 1.41 (1.15 to 1.71) for total respiratory diseases, pneumonia and COPD, respectively. The associations were not statistically significant for summertime temperature variability.Conclusion Wintertime temperature variability was associated with higher risk of incident respiratory diseases.