The risk of dying in a hospital from respiratory causes is greater in summer than in winter

2023-11-08 12:10:37

Global warming caused by climate change could increase mortality among patients hospitalized por respiratory diseases during the summer months. It is the main conclusion of a research led by the Barcelona Institute for Global Health (ISGlobal), a center promoted by the “la Caixa” Foundation, whose results have been published in The Lancet Regional Health. – Europe.

The findings can serve as a basis for better adaptation to climate change in health centersaccording to the authors.

The research team analyzed the association between ambient temperature and hospital mortality due to respiratory diseases in the provinces of Madrid and Barcelona between 2006 and 2019. The results showed that the number of hospital admissions in both provinces, including those that resulted in death, was highest during the winter months and lowest during the warm season (June to September), with a peak in the month of January and a minimum income in the month of August. However, although admissions were higher during the winter months, the highest incidence of in-hospital mortality occurred during the summer months and was strongly related to high temperatures.

To calculate the association between ambient temperature and hospital mortality, the team used data on daily hospitalizations, weather, and air pollutants.

To estimate the association between ambient temperature and hospital mortality, the team used data on daily hospitalizations, meteorology (temperature and relative humidity), and air pollutants (O3, PM2.5, PM10, and NO2). Although it has been widely described that daily exposure to heat and cold is associated with a higher risk of hospital admission for respiratory diseases such as pneumonia, chronic obstructive pulmonary disease (COPD) and asthmauntil now no study had focused on hospitalizations resulting in death and, therefore, on the most serious cases of morbidity.

Worsening of respiratory problems

In terms of attributable burden, the work has determined that high summer temperatures were responsible for 16% and 22.1% of the total fatal hospitalizations due to respiratory diseases in Madrid and Barcelona, ​​respectively. The effect of the heat was immediate, with most of the impact taking place in the first three days of exposure to high temperatures.

The effect of the heat was immediate, with most of the impact taking place in the first three days of exposure to high temperatures

“This suggests that the increase in acute respiratory problems during the heat is more related to the worsening of chronic and infectious respiratory diseases than to the spread of new infections, since these usually take several days to cause symptoms,” says Hicham Achebak, first author of the study and researcher at Inserm and ISGlobal.

The results of the study showed effects of heat especially for the acute bronchitis and the bronchiolitis, pneumonia and respiratory failure. Neither relative humidity nor air pollutants played a statistically significant role in the association of heat with mortality of patients admitted for respiratory diseases.

Women, more vulnerable

The research also shows that women were more vulnerable to heat than men. “This is most likely related to specific physiological differences in thermoregulation. Women have a higher temperature threshold above which sweating mechanisms are activated, and less sweat production than men, which translates into less heat loss through evaporation and, therefore, greater susceptibility to the effects of heat,” explains John Ballesterresearcher at ISGlobal and co-author of the work.

Unless effective adaptation measures are taken in hospitals, global warming could worsen the mortality burden of patients hospitalized for respiratory diseases during the summer period.

Hicham Achebak, first author of the study

The study has shown that high temperatures contributed to increasing the risk of mortality in patients hospitalized for respiratory diseases, while low temperatures were not associated with this variable. According to the research team, this could have to do with the fact that health services are increasingly prepared to deal with winter peaks in respiratory diseases.

In this sense, the results of the study have important implications for health policies. health adaptation to climate change, and for projections of the impacts of climate change on human health. “Unless effective adaptation measures are taken in hospitals, global warming could aggravate the mortality burden of patients hospitalized for respiratory diseases during the summer period,” says Hicham Achebak.

Reference:

Achebak H et al. “Ambient temperature and seasonal variation in inpatient mortality from respiratory diseases: a retrospective observational study”. Lancet Regional Health (2023).

Rights: Creative Commons.