Additional health care support needed to improve medication adherence among people with hypertension

American Heart AssociationOct 7 2021

People with hypertension, or high blood pressure, play a key role in whether they use medication appropriately to manage their blood pressure. However, a new American Heart Association scientific statement, published today in the Association's journal Hypertension, suggests additional support is needed for patients from the broader health care system. The statement urges health care professionals, pharmacies and insurance companies to develop specific, evidence-based strategies addressing medication adherence and create solutions for blood pressure control at the personal level for individuals with high blood pressure. A scientific statement is an expert analysis of current research and may inform future guidelines and recommendations.

The scientific statement, "Medication Adherence and Blood Pressure Control", summarizes the existing knowledge about the impact of medication non-adherence to the national prevalence of poor blood pressure control; the methods for measuring medication adherence and its associated challenges; risk factors for non-adherence; and strategies for improving rates of proper use of blood pressure medication individually and at the overall health system level.

According to the American Heart Association Heart and Stroke Statistics – 2021 Update, more than 55 million adults in the U.S. currently take medications to help with high blood pressure, and high blood pressure is a major risk factor for stroke, heart disease and kidney disease. Results from National Health and Nutrition Examination Surveys (NHANES) conducted between 1999 and 2018 revealed that, despite many high blood pressure treatment options, the percentage of people successfully managing their high blood pressure (high blood pressure measured in this study as ≥140/90 mm Hg) dropped 10% between 2014 and 2018, from 53.8% to 43.7%, respectively. Both percentages are far below the U.S. Health and Human Services' 2020 goal of 61% of adults with blood pressure <140/90 mm Hg.

A 2018 meta-analysis of studies in the U.S., Canada and Europe, by M. Lemstra et al., reported that 12% of people with hypertension never fill initial prescriptions. While many factors contribute to poor blood pressure management, proper medication usage plays a critical role. Medication adherence is complicated to define and address and requires solutions that manage more than one factor.

To reduce the massive risk for hospitalizations and deaths due to uncontrolled high blood pressure, specific attention is needed to understand why people don't take their medicine as prescribed. It's a factor that is highly modifiable. There are many reasons a person doesn't use or take medications properly, and a number of those reasons aren't in their control. As we look for strategies to support people with high blood pressure, we need to consider solutions that address other contributors, including the role of health care professionals and the health care system."

Niteesh K. Choudhry, M.D., Ph.D., statement's writing group Chair, professor of medicine at Harvard Medical School, executive director of the Center for Healthcare Delivery Sciences, associate physician in the division of pharmacoepidemiology and pharmacoeconomics and hospitalist at Brigham and Women's Hospital, Boston

The statement examines how best to measure adherence, as that continues to challenge professionals and individuals. Self-reported data and patient questionnaires continue to be inaccurate since people tend to overestimate how well they follow the prescribed regimen. Direct observation is, perhaps, the most accurate method, however, it is not practical in most situations. New technologies such as digital sensors, electronic medication dispensers and monitors and measurement of medication levels in a person's blood are increasingly available, yet many are not feasible in clinical practice.

The writing group indicates pharmacy refill databases may be the most accurate and efficient way to follow adherence for a large group of patients over time. However, it is also important to acknowledge that not all health systems have access to prescription refill information.

How to predict medication adherence remains complicated, according to the statement, which cites a 2003 World Health Organization (WHO) report. The WHO report categorizes risk factors for non-adherence into five dimensions:

• socio-economic and demographic,
• therapy-related,
• health care system or related to the health team, and
• individual and condition-related.

The way socio-economic and demographic dimensions impact adherence merits further research because these predictors were inconsistent across numerous studies. Access to care and cost of care are also barriers to proper adherence, in addition to the complexity of the medication regime and overall trust in the medical system.

The writing group highlights the relationship between the person with high blood pressure and their clinician as key to proper medication adherence, noting communication styles and trust matter, especially when making treatment decisions. This relationship is even more important when a person has other chronic health conditions, such as post-traumatic stress disorder (PTSD), alcohol or drug misuse, or dementia, each of which can adversely affect medication adherence.

The writing group reviewed research published since 2000 to identify effective interventions that may improve medication adherence. Suggestions to support and improve adherence fall into one of four categories: 1) patient education and counseling; 2) medication regime management; 3) reminders, monitoring and feedback; and 4) incentives.

The statement suggests several interventions are most likely to have success in promoting medication adherence:

• Health systems should develop a reliable method to assess adherence and offer resources to support patients. A pharmacy refill database is the best source of adherence information.
• Real-time counseling, open-ended discussions, visual aids and patient diaries are advised to engage individuals and improve health knowledge among people with high blood pressure.
• New technologies that integrate reminder notices, such as electronic pill devices that send text message notifications or have alert sounds, can support people to stay on track with their medication regime and routine.
• Health care professionals should evaluate ways to simplify the medication regime. One method may be prescribing a polypill or a fixed-dose combination pill – one tablet that contains multiple medications.
• Insurance companies should reduce or eliminate co-pays for prescriptions to address part of the financial barrier to medication adherence.
• Regular home blood pressure monitoring should be encouraged because measurements taken at home are often more accurate and predictive of cardiovascular issues than blood pressure readings taken at the doctor's office or hospital.

The writing group also suggests increasing the intensity of a person's high blood pressure treatment should not be postponed because they are not adhering precisely to the prescribed medication regimen. Postponing treatment changes can often lead to cycles of delays. The writing group noted that treatment intensification is safe when a person isn't taking medication as prescribed and can reduce the time it takes to control blood pressure levels, which is an important factor in reducing heart complications due to high blood pressure.

The Association's recently launched National Hypertension Control Initiative (NHCI) is focused on improving blood pressure rates across the U.S., with a special emphasis on historically under-resourced communities. The comprehensive program for professionals in community health centers includes regular blood pressure management training, technical assistance and resources that include the proper way to measure blood pressure, self-blood pressure management and measurement, medication adherence and healthy lifestyle options. In addition, the Association is collaborating with community-based organizations to provide the public with blood pressure resources and connections to health care professionals through trusted community channels.

This scientific statement was prepared by the volunteer writing group on behalf of the American Heart Association's Council on Hypertension; the Council on Cardiovascular and Stroke Nursing; and the Council on Clinical Cardiology.

Co-authors are Ian M. Kronish, M.D., M.P.H., FAHA; Wanpen Vongpatanasin, M.D.; Keith Ferdinand, M.D., FAHA; Valory N. Pavlik, Ph.D.; Brent M. Egan, M.D., FAHA; Antoinette Schoenthaler, Ed.D.; Nancy Houston Miller, B.S.N.; and David J. Hyman, M.D., M.P.H. Authors' disclosures are listed in the manuscript.

The Association is grateful for Dr. Hyman's expertise and leadership as the writing group chair for this statement, prior to his untimely passing on June 22, 2020.