Whether you currently smoke or you previously did and quit, you appear to be likelier to have a bad case of COVID-19 according to a new study by UCSF researchers.

The study looked at metadata for 11,590 COVID patients and found that the disease tended to progress into severe territory about twice as often among people who currently smoke or previously smoked. As KPIX reports, the data also points to e-cigarette users as being higher risk as well, due to "damage to upper airways and a decrease in pulmonary immune function in general."

The data tracks with what was already established about MERS, the infection caused by a different coronavirus, and in which it was found that smokers had higher rates of infection and mortality from the disease.

The new study looked at data from patients from 19 different other studies done so far in China, South Korea, and the United States, but those studies were mostly based on hospitalized patients and therefore might be skewed toward the more severe cases in general. Also, the study does not allow for any assessment of whether smokers are at any higher risk of contracting COVID-19 in the first place.

The conclusion of the study is simply that "Smoking is associated with substantially higher risk of COVID-19 progression,” as Professor Stanton A. Glantz, PhD, of the UCSF Center for Tobacco Control Research and Education says. "This finding suggests that California’s ongoing strong tobacco control measures that have lowered smoking may, together with the state’s other strong public health interventions, be contributing to California’s efforts to thwart the effect of COVID-19."

In other words, lower rates of smoking in California might be contributing to the overall lower death rate the state is seeing than in, say, New York or Louisiana.

The study looked at the cases of just over 2,100 patients who experienced serious disease progression. Of those, 731 (6 percent) had a history of smoking, and among the smokers, 218 cases (30 percent) saw the disease progress, compared with 17.6 percent among non-smoking patients.

There has been contradictory discussion in recent weeks citing the low prevalence of smoking among Chinese coronavirus patients, and data that some researchers have used to suggest that nicotine might inhibit the kind of inflammation associated with severer cases of the virus. But the UCSF paper does not give this much credence.

"The fact that smoking prevalence is lower among COVID patients than the general population has been cited as evidence for a protective effect of smoking,” says Roengrudee Patanavanich, MD, PhD, a visiting scholar at UCSF from the Department of Community Medicine at Ramathibodi Hospital at Mahidol University, Thailand. "But this low prevalence may actually be due to an under-assessment of smoking, especially when you consider the difficult conditions involved when caring for people in often overwhelmed health systems."

In other words, they may simply not have asked enough patients whether they were current or former smokers in Chinese hospitals.