Smokers have a greater probability of being hospitalised with Covid-19 and to eventually die from the disease, according to Biobank data from a study carried out in the United Kingdom.
The study put together both observational and genetic data on smoking and Covid-19, making it far more credible then previous studies which had ignored the latter. Led by Dr Ashley Clift at the University of Oxford, the researchers studied GP health records, Covid-19 test results, hospital admissions data and death certificates to identify links between smoking and Covid-19 severity from January to August 2020 in 421,469 individuals – all of whom had also previously had their genetic makeup analysed.
Clift and her team concluded that when compared to those who never smoked, current smokers were 80% more likely to be admitted to hospital and significantly more likely to die from Covid-19 if they became infected.
During the study period, 13446 (3.2%) people took a COVID-19 swab (PCR) test, 1649 (0.4%) of whom tested positive; 968 (0.2%) required admission to hospital; and 444 (0.1%) died as a result of their infection.
“Overall, the congruence of observational analyses indicating associations with recent smoking behaviors and [Mendelian randomization] analyses indicating associations with lifelong predisposition to smoking and smoking heaviness support a causal effect of smoking on COVID-19 severity,” they conclude.
“The idea that tobacco smoking may protect against COVID-19 was always an improbable one,” wrote Drs Anthony Laverty and Christopher Millet of Imperial College London, in an editorial.
Most (59%) participants had never smoked; over a third (37%) were former smokers; and only 4% were current smokers. Among current smokers, most (71%) were light or moderate smokers (1-19 cigarettes/day); only 29% were heavy smokers (20+/day).
via The Guardian
Dr Clift added that “Our results strongly suggest that smoking is related to your risk of getting severe COVID, and just as smoking affects your risk of heart disease, different cancers, and all those other conditions we know smoking is linked to, it appears that it’s the same for COVID. So now might be as good a time as any to quit cigarettes and quit smoking.
The study was first published in the Thorax journal.