Hypertension and hypercholesterolemia are leading chronic disease risk factors that contribute to excess morbidity, mortality, and healthcare expenses in the US. Poor management of these conditions can increase risks for negative health outcomes, most notably cardiovascular disease (CVD) events. “Effective antihypertensive and statin medications are available to lower CVD risk, but medication nonadherence could limit optimal management for patients with these conditions,” says Sandra L. Jackson, PhD.

Diet and physical activity modifications can improve hypertension and hypercholesterolemia for many people, but pharmacologic therapy is often required to optimize outcomes, according to Dr. Jackson. To reduce CVD risks, clinicians can tailor medications and have regular clinical interactions with patients to support them in remaining adherent to treatment. However, studies show that patients with both hypertension and hyperlipidemia have greater cardiovascular risks than those with either condition alone. As such, it is important to understand medication adherence for both conditions.

Seeking Clarity on Antihypertensive & Statin Adherence in Older Patients

For a study published in the American Journal of Preventive Medicine, Dr. Jackson and colleagues described adherence to antihypertensive and statin medications, individually and collectively, in Medicare Part D beneficiaries. “We examined variations in adherence by demographic and geographic characteristics,” explains Dr. Jackson. Examining factors relating to adherence, she notes, may help identify populations in greater need of services to support adherence, improve adherence among groups with the lowest adherence, and inform public health initiatives.

For the study, investigators examined adherence to antihypertensive and statin medications at the state and county levels using 2017 prescription drug event data for beneficiaries with Medicare Part D coverage. The authors also analyzed variations in adherence by race/ethnicity and by county of residence urbanicity (metropolitan, micropolitan, or rural). Beneficiaries with 80% or more days covered were considered adherent.

Medication Adherence Suboptimal, Disparities Persist

According to Dr. Jackson, the study showed that antihypertensive and statin medication adherence was suboptimal, and disparities were present. “Among the 22.5 million Medicare Part D beneficiaries prescribed antihypertensive medications, 77.1% were adherent,” she says. “Among the 16.1 million prescribed statin medications, 81.9% were adherent. Among the 13.5 million prescribed both antihypertensive and statin medications, 70.3% were adherent to both.”

Importantly, the study group also found that adherence varied by race/ethnicity. “Lower adherence was seen among American Indian/ Alaska Native, Hispanic, and non-Hispanic Black beneficiaries,” Dr. Jackson says. In addition, county-level adherence varied widely across the country, ranging from 25.7% to 88.5% for antihypertensive medications, from 36.0% to 93.8% for statin medications, and from 20.8% to 92.9% for both medications combined. Adherence to antihypertensive medications and/or statins was lowest in southern areas of the US (Table). “Our results highlight the need for efforts to remove barriers and support medication adherence, especially among populations at greatest risk for adverse cardiovascular outcomes,” says Dr. Jackson.

Collaborate With Patients to Find Solutions to Adherence Issues

Despite the development of interventions to improve blood pressure and cholesterol levels, additional public health and clinical efforts are needed to better address treatment adherence in this patient population. “To support adherence, clinicians can simplify treatment regimens by prescribing fixed-dose combination therapies,” Dr. Jackson says. “Clinicians can also work to build rapport with patients by asking about how well they are adhering to treatment and by inquiring about any potential barriers to adherence, such as costs or treatment side effects.”

Dr. Jackson notes that training resources are available to help build skills in conversations about adherence. “Such resources can help clinicians learn how to incorporate these discussions into routine care,” she says. “In addition, it’s important to support the implementation of programs that enhance continuity of care, teambased care, and pharmacist involvement because each of these factors may increase medication adherence. Furthermore, resources such as the Million Hearts Hypertension Control Change Package might be helpful. In future research, studies should be conducted to evaluate the effects of system-level or clinic-level programs to increase medication adherence.”