Association of debt delinquency at diagnosis and oral anticancer medication (OAM) adherence among patients with chronic myeloid leukemia (CML) or multiple myeloma (MM).

519 Background: Debt delinquency is common and precedes bankruptcy. However, unlike bankruptcy, the impact of debt delinquency on cancer treatment is not well understood. We hypothesized that patients with debt delinquency at diagnosis may struggle to afford and adhere to treatment, especially those with CML or MM, for whom OAMs are indicated at diagnosis. We examined the association between debt delinquency and OAM adherence among patients with CML or MM in Washington (WA) State. Methods: We conducted a retrospective analysis of patients with CML or MM diagnosed from 2012-2021 who initiated OAMs within 180 days. OAMs included Bcr-Abl tyrosine-kinase inhibitors (CML) and immunomodulators (MM). We used a unique database that links data from WA cancer registry, insurance claims (commercial plans, Medicare, Medicaid), and longitudinal TransUnion credit reports. We identified patients as having debt delinquency if they had past-due accounts within 50 days of diagnosis. Concordant with prior studies, we defined adherence as a medication possession ratio (MPR; drug supplied days divided by total days) of > 0.8 over 180 days. We performed nonparametric bivariate analyses and multivariable logistic regression (adjusting for age, sex, race, ethnicity, and insurance type) to test the association between debt delinquency and OAM adherence. Results: We identified 407 patients (109 CML, 298 MM) who were eligible, with a mean age of 65.8 years (SD 13.4); 56%, 87%, and 97% were male, white, and non-Hispanic, respectively. Most patients had either Medicare (45%) or commercial (31%) insurance. Approximately 12% of patients had debt delinquency at diagnosis. Across all patients, debt delinquency was significantly associated with mean age (56 vs. 67 years, P < 0.001), gender (16% female, 9% male, P = 0.04), insurance type (39% Medicaid, 11% multiple, 9% commercial, 7% Medicare, P < 0.001), and disease type (21% CML, 9% MM, P < 0.001). OAM adherence differed significantly by disease type; patients with CML and MM were 72% and 37% adherent, respectively. Among patients with CML, debt delinquency was not associated with OAM adherence (19% in adherent vs. 26% in non-adherent, P = 0.45 by bivariate analysis; OR 0.76, 95% CI: 0.24-2.39, P = 0.64 by multivariable analysis). In contrast, among patients with MM, debt delinquency was significantly associated with OAM adherence (4% in adherent vs. 12% in non-adherent, P = 0.02 by bivariate analysis; OR 0.27, 95% CI: 0.09-0.86, P = 0.03 by multivariable analysis). Conclusions: The differences in OAM adherence rates between patients with CML and MM and the impact of debt delinquency on adherence might be explained by OAM cost and access (i.e., generic drug available for CML versus proprietary only for MM). Therefore, interventions addressing personal debt delinquency may improve adherence among patients taking expensive OAMs.