Minorities and women who experience a stroke might be less likely to receive the clot-busting treatment, tissue plasminogen activator (tPA), according to a new study from Penn Medicine that was published in the online issue of Neurology.

“The use of intravenous tPA has increased dramatically over the past 10 years, but some eligible patients are still not receiving the treatment,” Dr. Steven R. Messé, associate professor at the Perelman School of Medicine at the University of Pennsylvania, said in a statement. “We wanted to understand which factors were associated with failing to treat these patients, so we can improve tPA use in the future.”

The study included more than 61,000 ischemic stroke patients in the U.S. between 2003 and 2011 who arrived at the hospital within two hours after the onset of symptoms and had no documented reason that they could not receive the treatment. The data came from the American Stroke Association’s “Get With The Guidelines — Stroke” registry.

They found that 25 percent of the eligible stroke patients didn’t receive the tPA treatment, but that the treatment rates did significantly improve over time. From 2003 to 2004, 45 percent of eligible patients received treatment compared to 82 percent from 2010 to 2011.

The researchers then adjusted for hospital and patient factors such as stroke severity and found that women had 8 percent greater odds of not receiving treatment than men. African-Americans had 26 percent greater odds of not receiving treatment than whites and those of other races had 17 percent greater odds of not receiving treatment than whites.

Previous studies uncovered similar findings, but this study included more contemporary treatment data, and comprehensively adjusted for potential known cofactors. The main thing it adjusted for was stroke severity, which is one of the most important predictors for short- and long-term outcome and a strong predictor of whether tPA should be administered.

Other patient-specific factors that were accounted for were: history of carotid stenosis, peripheral vascular disease, diabetes mellitus, heart attacks, presence of prosthetic heart valve, and not being transported to the hospital by EMS.

The study also found that patients who were treated at certified stroke centers were more likely to receive treatment than those at hospitals without certification. The patients who were not treated with tPA were admitted to hospitals with a smaller amount of beds, and were likely to not be teaching hospitals or Joint Commission-certified primary stroke centers.

“To improve use of the clot-busting medication, patients and families should be educated about potential stroke symptoms and encouraged to call EMS if stroke is suspected. Continued development of systems of care for stroke should remain a high priority, as well,” Messé said.

Inadequate access to treatment among minorities is not just an issue among stroke patients. Minority women are more likely to have aggressive breast cancer, yet receive inferior care, according to a study published in Cancer Epidemiology, Biomarkers & Prevent.

A Johns Hopkins study published in December 2015 found that poor and minority women with cancer have less access to minimally-invasive hysterectomies. Minorities are also less likely to have knee replacement surgery and more likely to have complications, according to a study published in the Journal of Bone and Joint Surgery last month.