Substance Use Tied to Increased COVID-19 Risk

Deborah Brauser

October 05, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

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 (NIH) assessed electronic health records (EHRs) 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 report.

In addition, those with a recent diagnosis of SUD were eight times more likely to develop COVID-19 vs 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

"The lungs and cardiovascular system are often compromised in people with SUD, which may partially explain their heightened susceptibility to COVID-19," co-investigator 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 healthcare services for a variety of reasons, including low socioeconomic status or stigma, she told Medscape Medical News.

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 September 14 in Molecular Psychiatry.

Is Nicotine Protective?

Volkow, her fellow senior author Rong Xu, PhD, Case Western Reserve University, Cleveland, Ohio, 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?"

Patients with SUDs have multiple medical comorbidities that are known risk factors for COVID-19, 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, she added.

Interestingly, a cross-sectional study published in April suggested that smoking may be protective against COVID, and 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 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/Latinx, and the others were classified as other or unknown.

EHRs were collected through June 15 at 360 hospitals in all 50 states and were de-identified to ensure privacy. SUDs included alcohol, tobacco, cannabis, opioid, and cocaine.

Racial Disparities

Results showed that about 7.5 million participants had a previous SUD diagnosis and, of these, 722,370 had been diagnosed within the past year.

Tobacco use disorder was the most common diagnosis (n = 6,414,580), followed by alcohol (1,264,990), cannabis (490,420), opioid (471,520), and cocaine (222,680).

In addition, 12,030 (60% women) were diagnosed with COVID-19 and 1880 had both COVID-19 and an SUD.

Adjusted analyses revealed that those who had a recent diagnosis of SUD were at a significantly greater increased risk for COVID-19 than individuals without an SUD (adjusted odds ratio [AOR], 8.7; 95% CI, 8.4 - 9.0; P < 10-30).

This increased risk was greatest in participants with opioid-UD (AOR, 10.2; 95% CI, 9.1 - 11.5; P < 10-30), followed by those with tobacco-UD (AOR, 8.2; 95% CI, 7.9 - 8.5; P < 10-30).

Alcohol, cocaine, and cannabis had AORs of 7.7, 6.5, and 5.3, respectively. The AOR for lifetime SUD and COVID-19 was 1.5.

Among all patients with COVID-19, hospitalization rates were significantly greater in those with an SUD (43.8%) vs those without (30.1%), as were death rates at 9.6% vs 6.6%, respectively.

Race was a significant risk factor. Black patients with a recent SUD diagnosis were twice as likely as White patients to develop COVID-19 (AOR, 2.2; P < 10-30), and those specifically with opioid use disorder were four times more likely to develop the disease (AOR, 4.2; P < 10-25).

Black patients with both COVID-19 and lifetime SUD also had greater hospitalization and death rates vs their White peers (50.7% vs 35.2% and 13% vs 8.6%, respectively).

"This surprised me," Volkow noted. "You can see the emergence of the racial disparities even under these conditions of really negative outcomes."

Vulnerable Populations

Cancer, obesity, HIV, diabetes, cardiovascular disease, and chronic kidney, liver, and lung diseases, which are all risk factors for COVID-19, were more prevalent in the group of patients with a recent SUD diagnosis vs those without.

In addition, asthma, type 2 diabetes, hypertension, obesity, and chronic kidney disease were more prevalent in the Black patents with a recent SUD than in the White patients.

Overall, the findings "identify individuals with SUD as a vulnerable population, especially African Americans with SUDs, who are at significantly increased risk for COVID-19 and its adverse outcomes," the investigators write.

The results also highlight "the need to screen and treat individuals with SUD as part of the strategy to control the pandemic while ensuring no disparities in access to healthcare support," they add.

Volkow noted that "marginalization" often occurs for individuals with addiction, making it more difficult for them to access healthcare services.

"It is incumbent upon clinicians to meet the unique challenges of caring for this vulnerable population, just as they would any other high-risk group," she said.

"Patients should not just be treated for COVID, but should also be provided with treatment for their substance use disorder," Volkow added.

"Pretty Convincing"

Commenting on the study for Medscape Medical News, Andrew J. Saxon, MD, professor in the Department of Psychiatry and Behavioral Sciences at the University of Washington School of Medicine, Seattle, called the findings interesting.

"I found it pretty convincing that people who have substance use disorders are probably at higher risk for getting COVID-19 infection and more complications once they are infected," he said.

Saxon, who was not involved with the research, is also director of the Center of Excellence in Substance Addiction Treatment and Education and is a member of the American Psychiatric Association's Council on Addiction Psychiatry.

He noted that an important point from the study was not just about a patient having an SUD being at increased risk for COVID-19 "and a more severe disease trajectory." Other factors associated with having an SUD, such as increased comorbidities, also likely play a part.

Saxon agreed that the ongoing opioid epidemic combined with the pandemic led to a "perfect storm" of problems.

"We were making slow but some progress getting more people the medications they need [to treat opioid-UD], but the pandemic coming along disrupted those efforts. A lot of healthcare entities had to shut down for a while, seeing patients only remotely," which led to barriers as many clinicians needed to learn how to proceed using telehealth options, said Saxon.

Universal Screening?

Asked whether physicians should screen all patients for SUDs, Saxon said it's a complicated question.

"Screening for tobacco and alcohol has a really good evidence base and practices should be doing that. The stigma is there but it's a lot less than with illegal substances," he said.

Screening for illegal substances or misuse of prescription substances may not be a good idea in healthcare settings "when it's something they can't do anything about. If you're going to screen, you would have to have either referral processes in place or treatment available in your facility," Saxon said.

Opioid use disorder is "especially amenable to treatment in a primary care or healthcare setting with prescribers," he noted.

However, stimulant or cannabis use disorders "require fairly intensive behavioral interventions that are not easy to deliver in many healthcare settings. And we don't have the workforce trained up to provide those treatments as widely as they should be," said Saxon.

"Unless there's some way to treat the issue, what's the point of screening for it? That just creates frustration for patients and clinicians, as well," he said. "It's something we're moving toward but we're not quite there yet."

The report authors and Saxon have disclosed no relevant financial relationships.

Mol Psychiatry. Published online September 14, 2020. Full text

Follow Deborah Brauser on Twitter: @MedscapeDeb . For more Medscape Psychiatry news, join us on Facebook and Twitter


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.