Reacción a "Reaction: risk of dying in hospital from respiratory causes is higher in summer than in winter"

I believe the study undoubtedly adds value, is of high methodological quality and covers a topical issue with an innovative approach. There was evidence of the impact of extreme cold or heat and temperature variability on the incidence of hospitalisations for respiratory diseases, but the impact of environmental temperature on in-hospital mortality after admission for respiratory reasons had not previously been assessed. Thus, this study does reveal an increased in-hospital mortality in summer, clearly related to high ambient temperature, which causes immediate effects 3 days after exposure, based on pneumonia, acute bronchitis, bronchiolitis, COPD or respiratory failure. This finding is in contrast to the incidence of hospitalisations for respiratory reasons, which are associated with the winter season.

Despite being an observational and retrospective study, it has a large sample size, a long evaluation period (14 years), reliable sources of morbidity and environmental data and high quality statistical analyses have been carried out with different perspectives, also taking into account confounding factors such as levels of major pollutants, relative humidity, age and variability in the quality of care due to the holiday period of health professionals. A limitation in the variables collected could be the absence of data on certain patient characteristics, such as other comorbidities; however, the available sample size and the epidemiological perspective can compensate for this lack.

We know that climate change causes adverse health consequences and this is one of them, which implies increased mortality in patients with pneumological diseases, which are very prevalent and a frequent reason for hospitalisation. In short, apart from preventive and corrective climate change policies, hospital facilities must be improved to reduce the thermal impact on hospitalised pneumological patients.