More than half of adults in the United States have been diagnosed with a chronic condition such as heart disease, diabetes, or hypertension, and 4 out of 10 adults are living with at least two such diagnoses [1]. Chronic diseases are the leading causes of disability and death in the United States, and the major contributor to the $4.1 trillion dollars spent in healthcare costs annually [1]. They account for 7 of every 10 deaths and affect the quality of life of 90 million Americans [1]. In New York State, nearly 1 in 4 hospitalizations and 6 out of every 10 deaths are due to chronic diseases [2]. The incidence of these diseases is even higher in economically disadvantaged areas and those with a predominance of racial and ethnic minorities like the South Bronx in New York City, where this study was conducted [2]. As of 2018, 37–42% of adults in the South Bronx were diagnosed with hypertension, in comparison to 28% of adults in New York City generally [2]. Similarly, the prevalence of diabetes in the Bronx in 2016 (up to 22%) was the highest of any county in the state [2]. Heart disease was the leading cause of death in Bronx County, at 201 per 100,000, compared to 184 per 100,000 in New York City, and 177 per 100,000 in New York State [2].
When considering the management of these disease states, adherence to chronic medications is of the utmost importance. Poor adherence to prescribed medication has significant implications including increased morbidity, mortality, and healthcare costs [3, 4, 5]. A 2003 report by the World Health Organization found that, on average, only 50% of patients adhere to their long-term treatments [6]. Non-adherence to medical therapies in the United States is the cause of up to half of all treatment failures [3]. In 2018 alone, medication non-adherence was associated with 25% of hospitalizations and contributed to approximately 125,000 deaths [3]. Furthermore, the costs of nonadherence are borne disproportionately by Black, Latino, and other minority groups. Nonadherence in these populations is higher due to a variety of factors including socioeconomic challenges, lack of access to pharmacies and primary care services, health literacy limitations, and lack of trust due to historical and structural discrimination outside of and within the medical system [6].
Patients at greatest risk of non-adherence include those with chronic illnesses like hypertension, diabetes, or hyperlipidemia, patients from racial and ethnic minority groups, and patients from socioeconomically disadvantaged groups [7, 8]. Adherence to long-term therapy is vital to preventing cardiovascular, neuropathic, renal, and other complications of such diseases. Additionally, these patients often have a larger burden of responsibility to correctly take several medications at various times within a 24-hour period.
Previous studies have demonstrated that pharmacists have a positive impact when promoting medication adherence in patient groups [4, 5, 9]. Pharmacists have utilized different approaches to impact adherence rates; these include communicating with patients face-to-face, virtually (through computer or telephone), and through focused individualized sessions [e.g., medication therapy management (MTM), chronic care management (CCM)] [7]. Little research exists regarding pharmacist lead interventions to improve medication adherence to chronic disease management medications (CDMM) in patients from racial and ethnic minority groups, and patients from socioeconomically disadvantaged groups specifically.
Several measures exist to accurately determine medication adherence. The two most common are proportion of days covered (PDC) and medication possession ratio (MPR) [10]. PDC is a percentage calculated by dividing the number of days covered in time frame by the number of days in time frame. MPR is a percentage calculated by dividing the sum of days' supply in time frame by the number of days in time frame. It is important to note that neither of these methods can confirm that the medication was administered as prescribed, however they do indicate that the patient had the medication on hand for use, and in this way serve as a proxy for medication adherence. The PDC threshold that is most widely used is 80% as it represents the level of medication adherence above which there is a reasonable likelihood of achieving the most clinical benefit [11].
This study aims to evaluate the impact of a structured intervention by pharmacists to improve adherence to chronic disease management medications and, consequently, Medicare Star Ratings, among patients predominantly from racial and ethnic minority groups.