May 11 (UPI) -- People who smoke or have chronic obstructive pulmonary disease, or COPD, may be at increased risk for severe complications and death from COVID-19 infection, an analysis published Monday by the journal PLOS ONE said.
Patients with COVID-19, the disease caused by the coronavirus SARS-CoV-2, are nearly twice as likely to experience severe illness if they have COPD and 1.5-times as likely to have severe illness, researchers at University College London reported.
Researchers reviewed data on 2,500 patients from 15 studies, finding that about 9 percent of patients were smokers and more than 2 percent had COPD.
"Despite the low prevalence of COPD and smoking in COVID-19 cases, COPD and current smokers were associated with greater COVID-19 severity and mortality," the authors wrote.
COPD is a common, persistent lung disease associated with reduced airflow. It affectes an estimated 251 million people worldwide.
About 1.1 billion people -- or 14 percent of the global population -- smoke, according to the World Health Organization.
Given the effects of SARS-CoV-2 on the lungs -- it has been linked with severe pneumonia in some patients -- the researchers in the new analysis sought to understand the prevalence and effects of COPD among those with the virus.
The researchers identified 15 papers -- based on epidemiological, clinical characteristics and features of COVID-19 and the prevalence of COPD -- that included data on 2,473 confirmed cases of COVID-19. Overall, 58, or 2.3 percent, of the patients also had COPD, while 221, or 9 percent, were smokers.
Overall, the authors of the analysis found that critically ill COVID-19 patients with COPD had a 63 percent risk of severe disease and a 60 percent risk of death, while critically ill patients without COPD had only a 33.4 percent risk of severe disease and 55 percent risk of death.
In addition, current smokers were 1.45 times more likely to have severe complications compared to former and non-smokers.
However, the researchers were not able to determine whether there was an association between the frequency of COPD flare-ups or severity of COPD with COVID-19 prognosis or complications.