Researchers at the University of Texas Medical Branch at Galveston looked at over 10,000 COVID-19 patients and found that significantly more former smokers ended up in the hospital and died from COVID-19 than those who still smoked or had never smoked at all.

Smoking can lead to increased risks of infections and worse outcomes for a range of diseases including pneumonia, tuberculosis, and rhinovirus, among others, but what about COVID-19? As scientists and medical experts race to learn more about the new disease, experts at UTMB looked at medical records and smoking habits of thousands of patients and found a surprising link between the new disease and the hard to break habit.

“COVID-19 predominantly effects the respiratory system and smokers are at risk of viral infections so we were interested in understanding the impact of coronavirus among smokers,” said Dr. Gulshan Sharma, senior author and professor and director of the Division of Pulmonary, Critical Care & Sleep Medicine at UTMB.
The team of doctors and researchers looked at the medical records of 10,216 patients who had tested positive for COVID-19 and provided information about their smoking habits. The majority, about 87 percent, indicated they’d never smoked while about 9 percent were former smokers and 3.9 percent said they were current smokers.
Former smokers were the group most likely to end up hospitalized or die because of COVID-19, their analysis found. In the past year, medical experts around the world have found that a number of different factors, including age, obesity, chronic kidney disease, diabetes, cancer, among others, can affect the severity of a COVID-19 infection and the likelihood that individual will end up in the hospital or die. Despite agreement about the association between severe COVID-19 and these comorbidities, the relationship between tobacco use and the severity of COVID-19 infection remains controversial, the researchers stated in the paper.
One variable that may be affecting the outcome of these patients is age. The risks of smoking-related disease result largely from cumulative damage; hence, the consequences of smoking occur disproportionately among the elderly, authors of the study said. In the study, the UTMB researchers estimated that the odds of hospitalization from COVID-19 increased by 6 percent for every year of age in the population studied.
“The risk of severe COVID-19 among former smokers is significantly driven by the effect of age and comorbidities,” said Dr Puebla Neira, first author of the study.
In the cohort the researchers studied, the mean age of former smokers was 10 years older than that of current smokers, and 12 years older than that of never smokers.
“Everyone should get vaccinated for COVID-19,” Sharma said. “Vaccine hesitant groups among former smokers should especially be encouraged to get vaccinated to reduce their risk of severe disease.”