Mexican American women show highest rates of medication nonadherence after stroke

Women who have had a stroke may be less likely than men to take medications to prevent a second stroke, with Mexican American women reporting the highest rates of nonadherence, according to new research published today in the Journal of the American Heart Association, an open access, peer-reviewed journal of the American Heart Association.

Our findings point to concerning disparities between men and women’s reports on taking stroke prevention medications routinely as prescribed, especially among Mexican Americans. Clinicians might consider screening for these factors and discussing the importance of not missing doses when prescribing these medications to patients to help reduce their risk of having another stroke.”

Lynda Lisabeth, Ph.D., M.P.H., FAHA, senior study author, professor of neurology and epidemiology at the University of Michigan in Ann Arbor

The study included more than 1,300 adults, ages 45 or older, who had a first ischemic stroke (caused by a blood clot or plaque blocking blood flow to the brain) between 2008 and 2019.

Researchers investigated whether participants reported taking their secondary stroke prevention medications as prescribed at 90 days after stroke. Four types of common stroke prevention medications were considered: antihypertensives to lower blood pressure; statins to reduce cholesterol; and antiplatelets and anticoagulants, two medications that reduce blood clotting.

The analysis found that 90 days after stroke:

• 11.5% of participants reported not taking their stroke prevention medications as prescribed.
• Women were more likely to report missing doses of cholesterol-lowering medications and antiplatelets, but not medications to reduce blood pressure, when compared to men.
• Compared to Mexican American men, Mexican American women were three times more likely to report not taking cholesterol-lowering medications as prescribed.
• Women who were older or married were also more likely than men to report missing doses of prescribed stroke prevention medications.

“We were surprised by the magnitude of the differences in medication-taking behaviors between men and women, especially among Mexican American women,” said study co-author Chen Chen, a Ph.D. candidate in epidemiology at the University of Michigan. “Our analysis reveals potential factors that may be exacerbating these disparities. For example, women in general and Mexican American women in particular are more likely to be caregivers for other family members. As a result, they may be less able to prioritize and manage their own health, which may contribute to a higher likelihood of medication nonadherence.”

The researchers said it was possible that the specific adverse effects of statins, such as muscle pain and weakness, may explain why more people reported not taking cholesterol-lowering medications as prescribed.

There were several limitations to the study. Participants self-reported how often they took their medications, therefore the results may be affected by recall bias. Some social and behavioral factors were not considered in this study, such as income and patients’ reasons for missing prescribed doses. Finally, study participants were from a single community in south Texas that predominantly included non-Hispanic white and Mexican American adults born in the U.S., so these findings may not be generalizable to other populations such as Mexican Americans who have immigrated to the U.S.

“The results of this study align well with previous observations from national databases and longitudinal population-based studies, which showed a higher frequency of nonadherence to secondary stroke prevention among females,” said Fernando D. Testai, M.D., Ph.D., FAHA, a professor of neurology and rehabilitation at the University of Illinois College of Medicine in Chicago, who also served as chair of the Association’s recent scientific statement Cardiac Contributions to Brain Health.

“The incremental value of this study lies in its examination of adherence during the critical few months after acute stroke, a period when the risk of experiencing a second stroke is highest. Addressing factors that contribute to sex-associated disparities in stroke care, particularly among racial and ethnic minorities, should be a top priority for a society that seeks to eliminate social inequalities and inequities.”

Study details, background and design:

• The data for this analysis was from the Brain Attack Surveillance in Corpus Christi (BASIC) Project, which recruited participants from Nueces County, Texas.
• The study included 1,324 adults, ages 45 or older, who had a first ischemic stroke between 2008 and 2019. Women comprised 48.4% of all participants; 58% of participants self-identified as Mexican American, 34.3% as non-Hispanic white and 7.7% as “other” race/ethnicity.
• In an interview with Spanish translation, participants were asked to show interviewers all pill bottles of the medications they were currently prescribed. For each of the four types of stroke prevention medications (antihypertensives, cholesterol-lowering medications, antiplatelets and anticoagulants), participants were asked: “How often in a typical week have you missed a prescribed dose of this medication? Never, Rarely, Occasional, Often, Very Often, Discontinued or Unfilled, or Don’t Know.”
• Researchers defined adherence to each prescribed medication as individuals reporting “Never” or “Rarely” missing a dose in a typical week, and all other responses were considered as non-adherence.

Lisabeth said future research is needed to investigate other factors not included in the current study that might contribute to sex differences in taking medications as prescribed, including psychological and interpersonal factors, such as patient concerns about potential side effects, patient perceptions of medication benefits, caregiving roles and whether patients received care from health care professionals of the same sex, which has been shown to improve medication adherence.

According to the American Stroke Association, more than 9 million Americans are stroke survivors, and about 1 in 4 stroke survivors suffers a second stroke. Women are disproportionately affected after a stroke, with more severe disability, higher risk of death and more recurrent strokes than men, the researchers noted. Research shows that taking secondary stroke prevention medications may reduce the risk of death and recurrent stroke. However, medication adherence after stroke is vital to reduce the risk and prevent additional strokes.