Factors Associated With Tyrosine Kinase Inhibitor Initiation and Adherence Among Medicare Beneficiaries With Chronic Myeloid Leukemia

Abstract

There is substantial concern surrounding affordability of orally administered anticancer therapies, particularly for Medicare beneficiaries. We examined rates of initiation and adherence to tyrosine kinase inhibitors (TKIs) among Medicare beneficiaries with chronic myeloid leukemia (CML) with and without cost-sharing subsidies. We selected TKIs given their effectiveness and strong indication for use among patients diagnosed with CML. Patients and MethodsUsing SEER-Medicare data, we identified individuals diagnosed with CML from 2007 to 2011. We used Cox proportional hazards regression to assess time from diagnosis to TKI initiation. We used generalized estimating equations to examine treatment initiation within 180 days and TKI adherence among initiators. We defined adherence as at least 80% of days covered during the 6 months after TKI initiation. Results Among 393 individuals diagnosed with CML from 2007 to 2011, 68% initiated TKI treatment within 180 days after diagnosis. In multivariate analysis, individuals with cost-sharing subsidies, younger age, lower comorbidity, and later year of diagnosis were significantly more likely to initiate TKIs. Among TKI initiators, 61% were adherent; adherence was lower for individuals age 80 years or older versus 66 to 69 years. ConclusionOnly 68% of Medicare beneficiaries with CML initiated TKI therapy within 6 months of diagnosis. Delayed initiation among individuals without cost-sharing subsidies suggests that out-of-pocket costs may be a barrier to timely initiation of therapy among individuals diagnosed with CML.

Association between insurance status at diagnosis and overall survival in chronic myeloid leukemia: A population‐based study

“…24, 25 In addition, given the chronic nature of CML treatment, expenses associated with monitoring and follow-up can limit adherence. 22, 26 These factors may have contributed to the poor outcomes seen both among the nonelderly uninsured population, and the insured patients over age 65 in this analysis, many of whom would have Medicare insurance.…”

“…However, these programs may have restrictions that exclude certain populations, including elderly patients on Medicare plans and undocumented immigrants. Indeed, previous research has identified cost-sharing as a potential barrier to TKI initiation and adherence among CML patients on Medicare, 8, 22 and patients with higher co-pays are more likely to stop treatment within the first 6 months. 8 In 2007 it was estimated that noncitizens comprise approximately 20% of the U.S. uninsured population; 23 undocumented immigrants comprise a disproportionate percentage of the uninsured, and following the Affordable Care Act (ACA) may represent up to 25% of the total uninsured population.…”

Out-of-Pocket and Health Care Spending Changes for Patients Using Orally Administered Anticancer Therapy After Adoption of State Parity Laws

“…4–7 In response, since 2008 43 states and Washington D.C. have passed laws to ensure parity in cost-sharing for oral and intravenous anticancer therapies (i.e., “oral chemotherapy parity” laws). 8 These laws are intended to ensure that cost-sharing for patients (e.g., copayments, coinsurance, benefit limits) is equivalent for anticancer drugs obtained with medical (intravenous) and pharmacy (oral) benefits.…”

Chronic Myeloid Leukemia—the Promise of Tyrosine Kinase Inhibitor Discontinuation

“…In 2007, 62.1% of all US bankruptcies were attributable to medical reasons, even though three quarters of these patients had health insurance, and bankruptcies attributable to medical problems rose by 49.6%, compared to 2001 [6]. High patient costs have been associated with non-adherence to TKIs in multiple studies [7, 8]. …”