Cigarette smokers face a much higher risk of hospitalization and death from COVID-19 compared to those who have never smoked, a new study suggests.
Researchers found that all smokers had higher odds of poor outcomes due to the virus, but those at the highest risk were heavy smokers, defined as those smoking at least one pack per day for more than 30 years.
These patients had nearly double the risk of death due to COVID-19 and were more than twice as likely to be hospitalized because of the disease.
The team, from the Cleveland Clinic, says its findings are the most complete evidence to date of a cause-and-effect relationship between smoking and an elevated risk of severe illness and death.
Researchers from the Cleveland Clinic looked at more than 7,000 coronavirus patients, including more than 6,000 never-smokers and the rest being current or former smokers (file image)
Patients smoking at least one pack per day for more than 30 years were 2.25 times more likely to be hospitalized and 1.9 times more likely from the virus than those who had never smoked before. Pictured: Chaplain Kevin Deegan places his hand on the head of a COVID-19 patient while praying for him at Providence Holy Cross Medical Center in Los Angeles, January 9, 2021
Research linking smoking status with severe COVID-19 infection and death has been limited and contradictory.
Early last year, the U.S. Food and Drug Administration (FDA) said that cigarettes can increase the risk of contracting the disease.
‘People who smoke cigarettes may be at increased risk of infection with the virus that causes COVID-19, and may have worse outcomes from COVID-19,’ the agency said in a statement.
The FDA has previously warned about ‘worse outcomes’ for coronavirus among smokers but did not specify what that meant.
In addition, a French study found that only 4.4 percent of 350 coronavirus patients hospitalized were regular smokers and theorized that nicotine could prevent the virus from infecting cells.
For the new study, published in JAMA Internal Medicine, the team examined data for all patients who tested positive for COVID-19 within the Cleveland Clinic Health system in Ohio and Florida between March 8, 2020 and August 25, 2020.
Of the 7,102 patients, the majority – 84.8 percent or 6,020 – had never smoked before.
Nearly 13 percent were former smokers and about 2.4 percent were current smokers.
A total of 341 were or had been smoking one pack per day between zero and 10 years, 400 had been doing so for 10 to 30 years, and 341 smoked one pack per day for more than 30 years.
Results showed that the longer patients had been smoking for, the higher their risks were for hospitalization and death.
Patients who had been smoking at least one pack per day for between 10 and 30 years were nearly 1.5 times more likely to be hospitalized after being diagnosed with COVID-19 than patients who were never-smokers.
Those consuming one pack per day for more than 30 years were 2.25 times more likely to be hospitalized from the disease.
Both also had about 1.5 times higher odds of being admitted to the ICU.
When it came to risk of death, people smoking for zero to 10 years had a 1.6 times higher odds of death, people smoking for 10 to 30 years had a 1.5 times greater risk of death than never-smokers.
For those smoking at least a pack per day for more than 30 years, patients were 1.9 times likely to die.
The team said there was no difference in the risk of hospital admission and death between current and former smokers.
‘The results of this study suggest that cumulative exposure to cigarette smoke is an independent risk factor for hospital admission and death from COVID-19,’ they wrote.