Analysis Confirms High Costs Impact Adherence to Cancer Drugs

Higher out-of-pocket costs contributed to lower patient adherence to oral cancer medications, according to a retrospective analysis published in the Journal of Managed Care + Specialty Pharmacy. Investigators found that adherence was less than optimal and was worse for patients with higher out-of-pocket (OOP) costs, those who were hospitalized, and those who received Medicare low-income subsidy.

Ami Vyas, Ph.D.

Investigators, led by Ami Vyas, Ph.D., aimed to identify the predictor of adherence to oral cancer medicines. They conducted a retrospective cohort study using data from Optum Clinformatics Data Mart claims database. Patients with a new pharmacy claim for an oral cancer medicine between July 1, 2010, and Dec. 31, 2017, were included, and adherence was assessed after six months of treatment. Vyas is assistant professor of pharmacy practice, specialized in the area of health outcomes research, at the College of Pharmacy, University of Rhode Island, in Kingston, Rhode Island.

Investigators included patients who received oral medications for blood, brain, breast, colorectal, liver, lung, ovarian, prostate, renal, or stomach. They selected these cancers because of their prevalence, higher mortality burden, and indications for oral medications. They did not include older oral endocrine therapies for breast cancer (tamoxifen, anastrozole, and letrozole). They indication that these drugs are generally inexpensive, have been extensively studied, are used to prevent cancer recurrence and metastasis and are not used as front-line cancer therapies.

Their review found that out of 37,938 patients with cancer, 51.9% were adherent to their cancer medication, with adherence ranging from 32.8% among those with liver cancer to 70.4% among those with brain tumor.

The average monthly out-of-pocket costs differed by cancer type, ranging from $749 among patients with blood cancer to $106 among those with prostate cancer. Higher costs were associated with higher odds nonadherence for many cancer types, including renal cancer (and breast cancer. Additionally, patients with inpatient hospitalizations had nonadherence for all cancer types except for stomach cancer.

They also found that the proportion of patients who discontinued medications varied by cancer, with 19.5% of patients with stomach cancer, 30.8% of those with renal cancer, and 49.1% of those with liver cancer who discontinued their cancer meds.

“Our findings suggest that it is crucial to address financial barriers and improve patients’ OAM access to achieve the favorable clinical outcomes demonstrated in clinical trials. Moreover, financial barriers can cause increased emotional distress in addition to the distress already brought on by a facing a life-threatening illness,” investigators wrote.

Of the limitations, investigators said they couldn’t assess adherence by cancer stage because the database used didn’t include cancer staging or dosing differences. Additionally, the database didn’t provide information on patients who may have received copay cards or other assistance or those who were uninsured.

The study was funded by the Pharmacy Quality Alliance and the National Pharmaceutical Council.