Substance use disorders (SUD), particularly opioid addiction and smoking, are tied to an increased risk for COVID-19 and serious adverse outcomes including hospitalization and death, new research suggests.
A study funded by the National Institutes of Health assessed electronic health records of more than 73 million patients in the United States. Although only 10.3% of the participants had an SUD, “they represented 15.6% of the COVID-19 cases,” the investigators reported.
In addition, those with a recent diagnosis of SUD were eight times more likely to develop COVID-19 versus those without such a diagnosis. For specific SUDs, the greatest risk was for those with an opioid addiction followed by those who were addicted to cigarettes.
Dr. Nora Volkow
coinvestigator Nora Volkow, MD, director of the National Institute on Drug Abuse, said in a press release.
It may also be harder for individuals with addiction to access health care services for a variety of reasons, including low socioeconomic status or stigma, she said in an interview.
Dr. Volkow said she has encountered patients with medical emergencies who refuse to seek treatment at the emergency department because of previous experiences where they have been mistreated and encountered discrimination, and “that’s really very tragic.”
The findings were published online Sept. 14 in Molecular Psychiatry.
Is nicotine protective?
Dr. Volkow, her fellow senior author Rong Xu, PhD, Case Western Reserve University, Cleveland, and their team conducted the study because data released before the pandemic showed a significant increase in opioid overdose in 2019. “We were in an opioid crisis where we again saw an increase in mortality associated with overdose – and then COVID comes along. So the question was how are people who are already struggling faring? And if they were getting infected [with the coronavirus], what happened to them?”
Dr. Rong Xu
Patients with SUDs have multiple medical comorbidities that are known risk factors for COVID-19, Dr. Volkow noted.
However, the only specific SUD that has been previously studied in this context is tobacco use disorder, she said. A report from Chinese investigators released early in the pandemic showed that smokers were more likely to be infected by coronavirus and more likely to die from COVID-19.
Interestingly, a cross-sectional study published in April suggested that smoking may be protective against COVID, and Dr. Volkow noted that a clinical study currently being conducted in France is assessing whether wearing a nicotine patch has the potential to prevent the virus.
“That’s very different from looking at a chronic smoker,” she pointed out. “It’s a potential that nicotine as a chemical [could be] a preventive measure as opposed to saying smoking will prevent you from getting COVID.”
Patients with SUDs, said Dr. Volkow, “are likely to be at greater risk because of the effects of drugs in the metabolic system and the interfering with oxygenation in the pulmonary vessels.”
The retrospective case-control study included EHR data from 73.1 million patients. In the study population, 54% were women, 55% were White, 10% Black, 2% Asian, 1% Hispanic/Latino, and the others were classified as other or unknown.
EHRs were collected through June 15 at 360 hospitals in all 50 states and were deidentified to ensure privacy. SUDs included alcohol, tobacco, cannabis, opioid, and cocaine.