Measuring Adherence to Oral Anticancer Medications: A Persistent Problem

Medication adherence, specifically whether patients are staying on the medications that they are prescribed, is a substantial health care quality concern. Medication nonadherence adversely impacts patients' health outcomes and contributes to an estimated $500 billion in medical costs annually. Oncology is no exception. With the rise in availability and popularity of oral anticancer medications, more cancer patients are treating their disease at home instead of in-hospital infusion centers.

Quality measurement is essential for assessing and improving patient adherence to oral medications. The Centers for Medicare & Medicaid Services (CMS) has recognized the impact of adherence measurement in its Medicare Advantage and Part D Star Ratings program by triple weighting the impact of these measures on plans' ratings and quality bonus payments. However, accurately measuring adherence is challenging. Direct measures (ie, observing drug administration or detecting the drug in a patient’s body) are impractical for quality improvement and accountability. Indirect measures (ie, assessing the proportion of days covered or medication possession ratio) are feasible but less accurate.

So, what is the path forward? Are oral anticancer medication adherence measures even necessary? As a starting point, the Pharmacy Quality Alliance (PQA) is tackling the problem by exploring the construction of oral anticancer medication measures. Other approaches to quality that consider communication and access are also essential to produce the best outcomes for patient adherence and should be considered.

The PQA Seeks New Measures

While the value-based world has seen development and implementation of adherence measures for chronic conditions, such as cardiovascular disease and diabetes, standardized and endorsed oral anticancer medication adherence measures remain elusive. To address this gap, PQA assembled a workgroup in 2023 to tackle the conceptualization of new quality measures for assessing the degree to which patients take their oral anticancer medications. Of note, PQA identified non-persistence as a separate measure concept from adherence, defined as lapses in therapy after a certain time period (eg, 90 days).

PQA came away from its project with three priorities to advance this work:

1. Compile available measure specifications for metrics currently used by organizations for internal assessments of adherence or persistence to oral anticancer medications.
2. Identify methodologies to assess oral anticancer medication adherence or persistence that may be appropriate for health plan performance.
3. Conduct initial feasibility and validity assessments of prioritized adherence or persistence methodologies.

Measuring adherence or persistence to oral anticancer medications presents novel challenges compared to other types of drugs, as summarized by Micah Cost, PharmD, MS, of the PQA in a recent blog.

• There are multiple types of oral anticancer medications available with different purposes.
• Oral anticancer medications are prescribed as part of complex regimens that often include atypical dosing schedules.
• Temporary discontinuation of therapy through drug holidays may confound efforts to measure adherence.
• Oral anticancer medications may be switched during therapy.

Due to the variety of oral anticancer medications across multiple cancer types, differences in the way these drugs fit into treatment regimens require different methods for calculating adherence or persistence. To this end, PQA announced in a recent webinar that their first step in exploring measure development has been to cluster oral anticancer medications into similar groupings to define broadly applicable approaches to measuring adherence or persistence. Presenters drew an analogy to diabetes medication measures that assess (1) the proportion of days (PDC) covered for diabetes medications and (2) persistence to basal insulin.

Though improving adherence to diabetes medications has demonstrated cost savings and better clinical outcomes, insulin users are excluded from the PDC measure because insulin requires titration and frequent dose adjustments that can impact the ability to calculate the measured result. Due in part to these measurement challenges, PQA created the persistence to basal insulin measure that assesses time from initiation to discontinuation of therapy and does not rely on the prescribed days’ supply for calculation. Similarly, measuring persistence rather than adherence may be useful for certain oral anticancer medications where lapses in treatment are expected but continuous use during a specific treatment period is desirable.

Looking Beyond Adherence and Persistence Measures

While developing oncology adherence or persistence measures would fill an important gap, other measure concepts can also promote improved adherence. In 2022, Real Chemistry convened a multistakeholder expert panel to define priority measure concepts for oral anticancer medications. The convening, which included patients, oncologists, pharmacies, community cancer centers, employers, oncology nurses, and payer representatives, identified priority concepts that considered, but went beyond, assessing adherence rates:

Screening for Oral Oncolytic Medication Access Challenges: As summarized in a 2022 Pharmaceutical Research and Manufacturers of America (PhRMA) report, longstanding inequities, racial and ethnic disparities, and social determinants of health (SDOH) influence medication access and adherence. Screening for medication access challenges, such as socioeconomic status or high costs, before prescribing oral anticancer medications and during treatment is essential to address factors impacting adherence. The workgroup recommended measuring documentation of screening and accompanying referrals in medical records. Importantly, more research is needed to identify best practices for screening and resolving access barriers, along with standardized and validated tools. PQA explored a quality measurement framework related to medication access and recommended developing a tool to identify issues related to health literacy, access to transportation, or inability of patients to pay for medications.

Bidirectional Patient and Provider Communication for Oral Oncolytic Treatment: Patient and provider communication regarding oral oncolytic treatment options and risks is a priority for measuring and improving quality. Bidirectional exchanges are vital to ensure patients and caregivers understand treatment options and accompanying risks, care teams understand threats to adherence, and all parties are positioned to manage risks throughout the care journey. As noted by Real Chemistry’s multistakeholder panel, this may necessitate development of new patient-reported survey tools that evaluate the extent to which these conversations are meaningfully improving understanding and adherence.

Although standardized and endorsed oral anticancer adherence or persistence measures could provide valuable insight into the problem of nonadherence, strategies for measuring interventions that improve access and communication should also be pursued. Focusing on medication access—particularly SDOH for vulnerable populations—aligns with the CMS Framework for Health Equity priorities. Expanding measures assessing bidirectional communication helps drive toward policymakers' longstanding goals to build meaningful, patient-centered quality measures.

Discussion question: What priorities should measure developers consider to help stakeholders understand and improve adherence or persistence to oral anticancer medications?

About Tom Valuck, MD, JD

Tom Valuck, MD, JD, is a Partner at Real Chemistry. He is a thought leader on health care system transformation and helps lead the firm’s focus on achieving better health and health care outcomes at a lower cost. Tom’s work at Discern includes facilitating the exploration of next-generation measurement and accountability models for health care delivery systems. He also helps clients develop strategies to achieve success within the value-based marketplace.

About David Blaisdell

David Blaisdell, a Director at Real Chemistry, leads and manages client projects, providing insight and subject matter expertise, particularly on quality landscape analyses and measure gap identification. David has led and contributed to projects focused on oncology quality measurement to identify key gaps in measures used in accountability programs and opportunities for measure development. Through this experience, David helps clients navigate measurement and value-based payments and define strategies for success.

About Real Chemistry
The Real Chemistry Market Access team uses research and strategic advisory services to help our clients improve health and health care through value-based payment and delivery models. These models align performance with incentives by rewarding doctors, hospitals, suppliers, and patients for working together to improve quality while lowering total costs. Real Chemistry is an independent provider of analytics-driven, digital-first research, marketing services, and communications to the health care sector.