Women, younger patients, and individuals from minority groups are significantly less likely to be adherent with their statins, and are at greater risk of hospitalization and death, a study has found.
In, researchers report the outcomes of a retrospective cohort analysis involving 347,104 adults with atherosclerotic cardiovascular disease and stable statin prescriptions, who were treated within the Veterans Affairs Health System.
Statin adherence – defined as a medication possession ratio of 80% or above – was 87.7%. Patients on a moderate intensity of statin therapy were slightly more adherent than were patients on low- or high-intensity therapy.
The lowest levels of adherence were seen in the youngest patients. Those aged under 35 years had a 60% lower likelihood of adherence compared with the reference group aged 65-74 years, and those aged 35-44 years had a 47% lower likelihood of adherence. From age 55 on, adherence improved.
Women were 11% less likely to be adherent to statin therapy than were men. Adherence was significantly different among persons of different racial backgrounds and ethnicities: black patients were 42% less likely to be adherent compared with non-Hispanic whites, Asian patients were 18% less likely to be adherent, and Hispanic patients were 27% less likely to be adherent.
. Among patients with a medication possession ratio less than 50%, 13.4% were hospitalized for ischemic heart disease or ischemic stroke, compared with 11.5% of patients who had a medication possession ratio of 90% or above, even after adjustment for baseline characteristics.
Researchers saw a dose-response association between lower adherence and higher mortality. The incidence of death in the first year was 8.8% in patients with a medication possession ration below 50%, 7.5% for those with a ratio of 50%-69%, 6.3% for those with a ratio between 70% and 89%, and 5.7% among those with a medication possession ratio at or above 90%.
This effect was slightly attenuated by adjustment for adherence to other cardiac medications, but the association remained significant.
“Although statins are among the most effective drugs for the secondary prevention of [atherosclerotic cardiovascular disease], low adherence is a common problem,” wrote Dr. Fatima Rodriguez of Stanford (Calif.) University’s Division of Cardiovascular Medicine, and her coauthors. “Minorities have not been well represented in statin-related trials and more work is needed to implement strategies to improve guideline adherence in these populations.”
Stanford’s Division of Cardiovascular Medicine supported the study. The investigators have received funding from the Doris Duke Charitable Trust, the Department of Veterans Affairs Health Services Research and Development Service, the National Lipid Association, and Duke Clinical Research Institute.
SOURCE: Rodriguez F et al. JAMA Cardiol. 2019 Feb 13. .