COVID-19 pandemic increased the magnitude of mortality risks associated with cold temperature in Italy: A nationwide time-stratified case-crossover study
Abstract
Backgrounds
The coronavirus disease 2019 (COVID-19) pandemic and some containment measures have changed many people’s lives and behaviours. Whether the pandemic could change the association between cold temperature and mortality remains unknown.
Objectives
We aimed to assess whether the association between cold temperature and all-cause mortality in the pandemic period has changed compared to non-COVID-19 period (2015-2019) in Italy.
Methods
We collected daily all-cause mortality data and meteorological data for 107 Italian provinces from 1, January 2015 to 31, May 2020. A time-stratified case-crossover design with the distributed lag non-linear model was used to examine the association between cold temperature and all-cause mortality during the first three months (from March to May in 2020) of the COVID-19 outbreak and the same months in 2015-2019.
Results
The relative risk (RR) of all-cause mortality at extreme cold temperature (2.5 th percentile of temperature at 3 °C) in comparison with the minimum mortality temperature (24 °C) was 4.75 [95% confidence interval (CI): 3.90-5.79] in the pandemic period, which is more than triple higher than RR [1.41 (95%CI: 1.33-1.50)] in the same months during 2015-2019. The shift in cold-mortality association was particularly significant for people aged 65-74 years [RR (95%CI): 5.98 (3.78-9.46) in 2020 versus 1.29 (1.10-1.51) in 2015-2019], 75-84 years [5.25 (3.79-7.26) versus 1.40 (1.25-1.56)], and ≥ 85 years [5.03 (3.90-6.51) versus 1.52 (1.39-1.66)], but not significant for those aged 0-64 years [1.95 (1.17-3.24) versus 1.24 (1.05-1.48)].
Conclusion
The findings suggest that the COVID-19 pandemic enhanced the risk of cold temperature on mortality in Italy, particularly among the elderly people. Further studies are warranted to understand the exact mechanism when detailed data are available.
Related articles
Related articles are currently not available for this article.