COVID-19 attributed mortality and ambient temperature: a global ecological study using a two-stage regression model.

Area of Science:

• Environmental Science
• Epidemiology
• Public Health

Background:

• A negative correlation between ambient temperature and COVID-19 mortality has been observed.
• The World Meteorological Organization (WMO) emphasizes sustained government interventions, warning against relaxing control measures due to warmer temperatures.
• Understanding the temperature-COVID-19 mortality relationship is vital for timely vaccination campaign planning.

Purpose of the Study:

• To evaluate the association between monthly ambient temperature, lagged by one month, and COVID-19 mortality.
• To analyze the impact of temperature on the number of COVID-19 deaths and the probability of high-level COVID-19 mortality.
• To provide a global perspective on the temperature-mortality relationship and inform public health strategies.

Main Methods:

• Utilized a two-stage regression model for cross-sectional and longitudinal analyses across 150 countries.
• Employed log-linear regression to standardize baseline disease burden by predicting pre-COVID-19 respiratory disease mortality.
• Applied negative binomial and logistic regressions to assess the temperature-mortality link, adjusting for pre-existing respiratory disease rates.

Main Results:

• A one-degree Celsius increase in ambient temperature was associated with a decrease in COVID-19 deaths (IRR=0.93; p<0.001).
• Higher ambient temperatures also reduced the probability of high-level COVID-19 mortality (OR=0.96; p<0.001).
• High-income, Northern Hemisphere countries experienced lower temperatures and higher mortality from both respiratory diseases and COVID-19.

Conclusions:

• The study corroborates a global negative association between ambient temperature and COVID-19 mortality.
• Longitudinal findings support the WMO's stance on the continued need for government interventions.
• Leveraging warmer temperatures can enhance public health responses, including optimizing vaccination campaign timing.