Direct causal relationship between smoking and COVID-19 outcomes: the work of CoEHAR researchers finds confirmations in an english cohort study. Compared with people who had never smoked, current smoking was associated with one-third lower risk of hospitalization
Covid-19 is a respiratory disease and the natural assumption is that smoking, a well-known risk factor for disease following infection from many respiratory viruses, is likely to worsen COVID-19.
The habit of lighting up a cigarette is one of the top leading causes of preventable deaths and a risk factor for many non-communicable diseases, which are important risk factors for developing severe COVID-19.
Several international researches have focused on the possibility that there is a direct causal link between smoking and Covid-19.
CoEHAR researchers had investigated the hypothesis, thanks to several studies over the last year, that while smoking is a risk factor for respiratory diseases, nicotine contained in it may represent a protective factor.
A cohort study conducted in England,”Association between smoking, e-cigarette use and severe COVID-19: a cohort study“, studied the data from 24 January 2020 until 30 April 2020 at the height of the first wave of the SARS-CoV-2 epidemic in England.
This was an open cohort study of all adults registered with 1205 general practices in England contributing to the QResearch database, representing 20% of English practices.
There were more than 8 millions adults in the cohort, of whom the 95.3% had recorded smoking status and were included in the analyses. There were 69 047 (0.9%) recorded as using e-cigarettes, of whom 3251 (4.7%) were recorded as never smoking, 35 267 (51.1%) as formerly smoking and 30 529 (44.2%) as currently smoking.
Compared with never smokers, people currently smoking were at lower risk of COVID-19 hospitalization. Similar data for ICU admission, and mortality. No hightened risk was observed among e-cigarette users.
Although a direct causal link has not yet been established, analyzing the various published studies, including those of CoEHAR, it can be highlighted how further research may focus on a possible pharmaceutical role of nicotine in the treatment of Covid-19 infection.