Medication adherence is critically important to patients’ outcomes. Non-adherence to medication is responsible for approximately 33% to 69% of medication-related hospitalizations and also may result in direct health care spending of $300 billion in the United States annually.1

Furthermore, the CDC presented data that demonstrate that medication non-adherence is connected with approximately 50% of treatment failures in chronically ill patients and 125,000 deaths per year.1

At the Pharmacy Quality Alliance (PQA) 2020 Annual Meeting on Thursday, speakers discussed some of the drivers of medication adherence in community pharmacy.2

In order to measure medication adherence accurately, speaker Ben Urick, PharmD, PhD, research assistant professor at the University of North Carolina Eshelman School of Pharmacy, used the proportion of days covered (PDC). PDC can be used to assess the ratio of number of days the patient is covered by a medication in a period to the number of days the patient is eligible to have the medication on hand. This measurement allows researchers to have an accurate understanding of medication adherence among patients.2

Urick explained that when using PDC to analyze data, he found that there are some drivers for medication adherence in community pharmacy that are purely logical. He found that the 2 services that correlated the strongest with positive results in medication adherence were offering home delivery and offering multi-dose compliance packaging.2

Urick found that patients with 90-day prescriptions had a higher adherence due to a lack of a gap in coverage. In his research, he observed that 30-day prescriptions allowed for a potential delay in access that could directly cause difficulty in medication adherence.2

“Patients filling 90-day prescriptions have greater adherence scores than patients who do not. In a recent study, the researchers found an 8% to 12% difference in adherence between those who fill 90 days and those who do not,” Urick said.2

Similarly, patients who receive their prescriptions through mail-order presented higher medication adherence because of similar reasons in ease of access. Urick explained that the reason for this was due to the fewer number of opportunities available for patients to experience a gap in coverage.2

“Looking at 90-day fills, there are really only 3 gaps throughout the year that a patient could witness uncovered time, whereas if a patient is filling every 30 days, then every month you have a potential observation window for uncovered time,” Urick said.2

In the calculation of the PDC using 90-day fills, Urick explained there also exists the potential for an inflation of observations of medication adherence due to a lack of knowledge of whether patients having the pills on hand is a true sign of them putting pills in their mouths.2

“Taking this into consideration, we know that PDC isn’t perfect, and you’d be hard pressed to find someone who says it absolutely is. But we also know that there’s a lot of evidence that, even when taking into account all the imperfections, PDC is still well correlated with outcomes,” Urick said.2

REFERENCE
  1. Urick BY, Kumar A, Farley JF. Measuring Adherence: A Proof of Concept Study for Multiple Medications for Chronic Conditions in Alternative Payment Models. Pharmacy (Basel). 2019;7(3):81. doi: 10.3390/pharmacy7030081.
  2. Urick B, Farley J, Bhosle M. Exploring Drivers of Community Pharmacy-Level Performance on Adherence Measures. Presented at PQA 2020 Annual Meeting, May 14, 2020.