AMCP 2022: High Out-of-Pocket Costs Are Associated with Nonadherence Among Patients Taking Oral Cancer Drugs

Oral cancer treatments are becoming increasingly common and have many advantages, especially the convenience of “popping a pill” at home. Despite that, data presented at the Academy of Managed Care Pharmacy’s annual meeting showed that almost half of patients are nonadherent. High out-of-pocket costs and low income contribute to patients not taking the medication as prescribed.

Ami Vyas, Ph.D., M.S., MBA, an assistant professor of pharmacy practice at the University of Rhode Island College of Pharmacy and her colleagues found that 48.1% of the almost 38,000 patients with cancer in their study were nonadherent to oral cancer treatments.

Ami Vyas

In an email to Managed Healthcare Executive®, Vyas explained that injectable therapies are generally covered under medical benefits in patients’ insurance plans, whereas oral drugs are covered through prescription drug plans that may charge coinsurance (a percentage of the drug’s cost; if the drug is expensive, the out-of-pocket expense is high).

“A very limited number of oral anti-cancer medications have injectable equivalents, and most of the newer oral anti-cancer medications don’t have any,” Vyas wrote. “If there is no alternative to oral medications, then it leaves patients with no choice but to fill the expensive oral medications or abandon the prescription if they cannot afford it.”

Vyas and her colleagues used the de-identified Optum De-identified Clinformatics Data Mart commercial claims database for 2010-2018 to conduct their study. Patients with a proportion of days covered of less than 0.8 were classified as nonadherent. Proportion of days covered is a standard way of gauging adherence using claims data. It is the ratio of the number of days covered by the prescribed medication to the number of days the patient is eligible to have the medication on hand.

The proportion of adherence varied with the type of cancer, they found. It was lowest for patients with liver cancer; just 32.8% were adherent. It was highest (70.4%) for patients with brain tumors. Vyas and her co-researchers also found large differences in the monthly out-of-pocket costs by the type of cancer. Patients with blood cancer had the highest monthly out-of-pocket cost, $749. Patients with prostate cancer had the lowest, $106.

Further analysis showed that higher out-of-pocket costs were associated with greater odds of nonadherence for most of the types of cancer in the study.

The results also show that patients with renal or stomach cancer with Medicare low-income subsidy were more likely to be nonadherent than those with commercial insurance.

“Similar to previously published studies, we found that higher out-of-pocket costs [were] a predictor of nonadherence with oral anti-cancer medication for a majority of cancer types,” Vyas said, adding that the association can be partly attributed to the introduction of several expensive targeted oral anti-cancer medications in the past decade, resulting in higher patient out-of-pocket costs.

Vyas said she supports efforts to reduce patient cost sharing in order to reduce the financial barrier to accessing the medication.

Patients who were hospitalized or received concomitant injection chemotherapy were more likely to be nonadherent with oral anti-cancer medications, Vyas noted. “Strategies and interventions that promote adherence across care settings may be useful,” she said.

The researchers also looked at male-female differences in adherence. In four out of eight cancer types where the role of gender was examined, they found that men were less likely to be nonadherent than women. “We can only surmise possible reasons for this,” Vyas wrote. “For example, it is possible that women were more likely to develop toxicity resulting in treatment interruption.”