Coronavirus warning for smokers: Public Health England says addicts face greater risk of coronavirus

Leading experts who have scoured all of the available evidence collated so far say the proof smoking raises the risk of coronavirus is limited.

The group of experts even admitted warnings made by health chiefs were based mainly on assumptions, given the known infection risks of smoking. 

The team, based at the Harvard School of Dental Medicine and the University of Crete in Greece, reviewed five of the first studies on smoking and COVID-19.

Research showed smokers do face a greater risk of suffering complications but others suggested they were less likely to be infected in the first place.

The review of the evidence, led by Harvard’s Dr Constantine Vardavas, was published in the journal Tobacco Induced Diseases. 

Study 1:  Wei Liu and colleagues at three tertiary hospitals in Wuhan, China.

How many people were involved?

78

How many of them were smokers?

Unclear

Where were the results published?

Chinese Medical Journal 

What did it find?

The patients who progressed had a ‘significantly’ higher number smokers compared to the patients who got better – 27 per cent compared three per cent.

Study 2: Guan et al at 552 hospitals in 30 provinces or regions of China.

How many people were involved?

1,099

How many of them were smokers?

A total of 12.6 per cent (137) were current smokers and 1.9 per cent (21) were former smokers.

Where were the results published?

The New England Medical Journal  

What did it find?

Among the 173 patients with severe symptoms, 16.9 per cent (29) were current smokers and 5.2 per cent (nine) were former smokers.

In comparison, 11.8 per cent (108) of the 926 with milder symptoms were current smokers, and 1.3 per cent (12) were former smokers.

In the group of patients that either needed mechanical ventilation, admission to an ICU or died, 25.5 per cent were current smokers and 7.6 per cent were former smokers.

But in the group of patients that did not have these adverse outcomes, only 11.8 per cent were current smokers and 1.6 per cent were former smokers.

Study 3: Jin-jin Zhang and colleagues at No. 7 Hospital of Wuhan, China.

How many people were involved?

140

How many of them were smokers?

Some 6.4 per cent were either current smokers (two) or past smokers (seven).

Where were the results published?

Allergy

What did it find?

Among the 58 patients who severely ill, 3.4 per cent (two people) were current smokers and 6.9 per cent (four) were former smokers.

In comparison, of the 82 with milder symptoms, none were current smokers and 3.7 per cent (three) were former smokers. 

Study 4: Fei Zhou and colleagues at Jinyintan Hospital and Wuhan Pulmonary Hospital, Wuhan, China.

How many people were involved?

191

How many of them were smokers?

Six per cent (11 people) were current smokers

Where were the results published?

The Lancet

What did it find?

Among those that died (54), nine per cent (five people) were current smokers. Of those who survived, four per cent (six people) were smokers.

Study 5: Chaolin Huang, of Jin Yin-tan Hospital, Wuhan, China, and colleagues.

How many people were involved?

41

How many of them were smokers?

Seven per cent (three people) were current smokers

Where were the results published?

The Lancet 

What did it find?

None of the 13 patients who needed to be admitted to ICU were current smokers. In contrast, 11 per cent (three) of those who did not need intensive care were smokers.

ARE THE STUDIES REPRESENTATIVE OF THE REAL SMOKING POPULATION? 

In all of the studies, fewer than 15 per cent of the patients were smokers – a figure that clashes with China’s smoking rate. 

The WHO says 300million people in China smoke – roughly a fifth of the country’s total population and a third of the world’s total.

Data from a national survey conducted by China in 2015 found up to 60 per cent of men between the ages of 45 and 64 smoke.

British researchers were clueless as to why the NEJM study, the largest studies on this topic, had such low rates of smokers (12.6 per cent), especially given 28 per cent of patients were between 50 and 64.