We can add another two studies to the list of preliminary reports that mention smoking and Covid-19.
The first, published on Saturday and entitled ‘Factors associated with hospitalization and critical illness among 4,103 patients with Covid-19 disease in New York City’, is an interesting read.
It concludes that the strongest risks for hospital admissions were age and comorbities (pre-existing illnesses). On the issue of smoking, the key paragraph reads:
Surprisingly, though some have speculated that high rates of smoking in China explained some of the morbidity in those patients, we did not find smoking status to be associated with increased risk of hospitalization or critical illness.
The second is a French study. I can’t read French so I am indebted to Danish journalist and blogger Klaus K who tweeted:
Official French data on #tobacco smoking & #covid19 replicate the picture in China, Germany & USA: A remarkable low rate of smokers are hospitalised w/ coronavirus compared to smoking prevalence (France 23%).
A link to the data can be found here.
These are not the only examples of smokers being found to be under-represented among hospitalised or critical coronavirus patients.
On March 31 the Centers for Disease Control and Prevention (CDC) in the USA posted preliminary estimates of the prevalence of selected underlying health conditions among patients with coronavirus.
The CDC results were summed up in another tweet by Klaus K:
The consistent low rate of #tobacco smokers among patients with #coronavirus in China is now duplicated in the US by CDC. Among 7,162 corona patients with medical records, 6,901 were never-smokers (96.3%), 165 ex-smokers (2.3%), and only 96 smokers (1.3%).
The CDC study followed reports of two meta-analyses of studies based on patients in China that I wrote about here.
According to a preliminary meta-analysis published in the European Journal of Internal Medicine (sample size: 1,399), 'Researchers found no link between cigarette smoking and the severity of Covid-19 among cases in China.'
In another, ongoing, meta-analysis, cardiologist Dr Konstantinos Farsalinos has reported that of '2,352 hospitalized cases examined, the observed prevalence of current smoking is <1/3rd the expected.'
Interestingly, the Foundation for a Smokefree World is compiling its own ‘Covid-19 and Smoking Updates’.
Posted on Friday by Charles Gardner, the Foundation’s director of Health Science and Technology, this is his current analysis:
Smokers who become ill with Covid-19 are no more likely to be hospitalized than non-smokers.
13 studies from China covering 5,960 hospitalized Covid-19 patients show that only 6.5% of them were smokers. The smoking rate in China is 26.6% (50.5% male and 2.1% female).
US Centers for Disease Control and Prevention (CDC) data on 7,162 Covid-19 patients show that only 3% of those who required hospitalization were current smokers. The smoking rate in the United States is 13.7% (15.6% male and 12% female)
To the best of my knowledge none of the studies mentioned above have been reported by a single mainstream newspaper or broadcaster in the UK or US.
Only one smoking and Covid-19 related ‘story’ has been reported and that was a statement issued on Friday April 3 by Public Health England that declared:
‘Emerging evidence from China shows smokers with Covid-19 are 14 times more likely to develop severe respiratory disease’
See ‘Smokers at greater risk of severe respiratory disease from Covid-19’.
Based on a single study that analysed just 78 patients of whom only five were smokers, this alarmist anti-smoking propaganda has been reported at home and abroad without, as far as I can tell, any counter argument.
The only journalist who has queried PHE’s ‘story’ is Rod Liddle. Writing in the current issue of the Spectator, Rod cites some of the evidence PHE chose to ignore. The article can be found in the print edition, out now. Online it is available only to subscribers but if that changes I’ll let you know.
Meanwhile, based on all the current evidence, how do we summarise the threat of Covid-19 to smokers in particular?
If you have an existing respiratory illness, possibly caused or exacerbated by smoking, it’s reasonable to think you may be at greater risk of hospitalisation or critical illness if you catch a respiratory virus such as Covid-19. That much is common sense.
So far however there would appear to be very little evidence that smokers per se are at greater risk of hospitalisation or chronic illness than non-smokers. Indeed, in most of the preliminary studies smokers are under-represented in terms of hospitalisation and critical illness.
One or two studies even hint that smokers might be protected from Covid-19. Personally I think it’s too early to draw any conclusions either way.
On current evidence however it’s clear that if there is an outlier among the present crop of studies and meta-analyses, it’s the study that Public Health England has used to justify the contentious claim that ‘smokers with Covid-19 are 14 times more likely to develop severe respiratory disease.’
Unscientific propaganda has no place in public health and in due course PHE must be held to account.