(NewsNation) — Only 22% of the estimated 2.5 million adults with opioid use disorder in 2021 received medications to treat it, according to a recent study.

The findings published in JAMA Network Open revealed that some groups were far less likely to receive medication treatment, including Black people, women, those unemployed and those living in rural areas.

Researchers used data from more than 47,000 adults aged 18 or older who participated in the 2021 National Survey on Drug Use and Health. Among the 2.5 million who had opioid use disorder in the past year, 52.5% were men, 67.4% were 35 years or older, 60.6% were non-Hispanic white and 52% lived in large metropolitan areas, according to the study.

Only 36% received any substance use treatment, and only 22.3% received medications for opioid use disorder. Of those who did receive treatment, 58.5% were men, 61.7% were 35 or older, 67.1% were non-Hispanic White and 57.7% lived in large metropolitan areas.

“More than 80,000 people are dying of a drug overdose involving an opioid every year, while safe and effective medicines to treat opioid use disorder are sitting on the shelf unused,” said Dr. Wilson Compton, deputy director of the National Institute on Drug Abuse and senior author of the study.

Researchers found that people with opioid use disorder receiving substance use treatment via telehealth were about 38 times more likely to also receive medications compared to those who did not receive telehealth treatment.

“This study adds to the growing evidence that telehealth services are an important strategy that could help us bridge this gap, supporting the delivery of safe, effective, and lifesaving care for people with opioid use disorder,” Compton said in a news release.

Nora Volkow, director of the National Institute on Drug Abuse, which helped fund the study, said “medications for opioid use disorder are safe and effective” and “help sustain recovery and prevent overdose deaths.”

“Failing to use safe and lifesaving medications is devastating for people denied evidence-based care. What’s more, it perpetuates opioid use disorder, prolongs the overdose crisis, and exacerbates health disparities in communities across the country,” Volkow added.

According to the Centers for Disease Control and Prevention, nearly 107,000 people died of a drug overdose in 2021. Over 75% of those involved an opioid, such as fentanyl.

Overdose deaths have skyrocketed over the past two decades, and several retailers, including Walmart and CVS, have settled lawsuits worth millions of dollars alleging they exacerbated the epidemic.

This year, the CDC has warned that fentanyl is increasingly being laced with xylazine, an animal sedative that can slow the heart rate to fatal levels.