Evidence on smoking and Covid-19 deaths flimsy at best – Dwaine van Vuuren

At the start of the Covid-19 pandemic; smoking was listed by many countries as a risk factor for those that caught the virus. The World Health Organisation stated that Covid-19 primarily attacked the lungs and said “smoking impairs lung function making it harder for the body to fight off coronaviruses and other diseases.” The Organisation concluded in a statement on 11 May 2020 that “available research suggest that smokers are at a higher risk of developing severe disease and death” and also urged for caution about “amplifying unproven claims that tobacco or nicotine reduce the risk of Covid-19”. It follows a French study by Prof Jean-Pierre Changeux from France’s Pasteur Institute that concluded that nicotine can help the body combat the Covid-19 infection. The professor and his team are currently preparing to launch a human trial to test their hypothesis. The South African Government used the WHO’s advice when they adopted the controversial decision to ban the sale of tobacco programme; a policy that they have stubbornly stuck to despite a legal challenge, widespread condemnation and a blooming blackmarket. Minister Nkosazana Dlamini-Zuma has cited scientific studies to back up her claim that that there is a direct link between severe Covid-19 plus an increased risk of catching the disease in the first place for smokers. The claims and counterclaims about the effect of smoking on Covid-19 patients has prompted Dwaine van Vuuren from RecessionAlert to take a closer look at the demographics of smokers and Covid-19 deaths per million and he found that evidence on a link is “tenuous at best” for men but female smokers do appear to be more at risk. – Linda van Tilburg

Linkage between smoking and Covid-19 deaths is tenuous at best

By Dwaine van Vuuren*

Given the huge media coverage and controversy surrounding the smoking ban in South Africa’s lockdown regulations, we set about to see if there was any statistical relevance to be seen between 137 individual country smoking demographics and Covid-19 deaths per million.

The results were quite surprising, with an almost negligible correlation (r-square = 0.012) between percentage of population male smokers and Covid-19 deaths per million. We expected this to be a lot higher:

A lot less woman smoke than men. This is consistent among almost all 137 countries we examined.

The interesting thing however is that there is a much more meaningful (but weak nonetheless) correlation (r-square = 0.17) between percentage of females who smoke and Covid-19 deaths:

If we assume population demographics of 50:50 male-to-female we can compare countries’ total populations as shown below, which is still a very low correlation.

The percentage of the population that smoke has almost no bearing on Covid-19 deaths per million:

The maximum correlation we could coax out of the total population data set above was to only consider countries with a death rate of higher than 75 per million. Only 21 countries qualified, namely Mexico, Panama, Iran, Denmark, Germany, Brazil, Portugal, Luxembourg, Canada, Ecuador, Switzerland, United-States, Ireland, Netherlands, Sweden, France, Italy, United-Kingdom, Spain, Andorra and Belgium. We used the 21% of adult population that smokes in South Africa to project the most likely deaths per million of South Africa, assuming this is the true statistical relationship that holds among smoking and Covid-19 deaths:

At 300 deaths per million and a population of 59 million that gives us 17,700 deaths projected for South Africa. This is of course a highly selective and small subset of the total sample and assumes SA will be among the top-22 countries in the world when it comes to deaths per million.

On the surface it looks like the linkage between smoking and Covid-19 mortality is very tenuous. There are far higher linkages with age and other co-morbidities such as weight and cardiovascular issues.

  • Dwaine van Vuuren has a Bachelor of Science Honours degree majoring in mathematics, computer science and statistics and is a full-time trader, investor and quantitative analyst. His passion for numbers and keen research and analytic ability has helped grow RecessionALERT into a company used by hundreds of hedge funds, brokerage firms and financial advisers around the world.