Association of Patient Characteristics and Insurance Type with Multiple Myeloma Care Patterns

Background: Studies reporting disparities inmultiple myeloma (MM) care patterns are mostly limited to Medicare Parts A & B beneficiaries. Moreover, little is known about access to triplet regimens and expensive prescription oral medications such as lenalidomide.

Objective: To examine the use of novel triplet regimens and lenalidomide in induction therapy, as well as stem cell transplantation (SCT) by race and social determinants of health (SDOH), among patients with newly diagnosed MM.

Methods: This retrospective cohort study used Taussig Cancer Center's Myeloma Patient Registry to identify adults with newly diagnosed MM between January 1, 2017- December 31, 2021, and treated in northeast Ohio. Patients who had at least 1 year of follow-up since the initial MM diagnosis were included. Electronic health records and Surescripts dispensed prescription data were used to capture during the first year after initial MM diagnosis 1) prescription fill for lenalidomide and 2) use of any triplet regimens (including bortezomib, lenalidomide, and dexamethasone; bortezomib, cyclophosphamide, and dexamethasone; carfilzomib, lenalidomide, and dexamethasone; daratumumab, lenalidomide, and dexamethasone; ixazomib, lenalidomide, and dexamethasone; and bortezomib, thalidomide, and dexamethasone), and 3) receipt of SCT during the study follow-up. Multivariable logistic regression models were used to examine the association between patient race, sex, age at initial diagnosis, insurance type, area deprivation index (ADI), Eastern Cooperative Oncology Group (ECOG) Performance Status, Charlson comorbidity index (CCI), diagnosis year, treatment location, and the outcomes of interest. Lenalidomide model was also adjusted for the presence of chronic kidney disease (CKD).

Results: We identified 569 patients with a median age of 66 years (IQR, 59-73), median CCI of 2 (IQR, 0-5), and median ECOG of 1 (IQR, 0-1); 55% were male, 76% White, 23% Black, 1.1% other races. The majority had Medicare (51%); 38% had private insurance, 8.3% had Medicaid, and 1.8% were self-paying or had other payors. Overall, 73% had at least one fill for lenalidomide (76% in White, 68% in Black, and 50% in patients with other racial backgrounds, p=0.07) and 64% received any triplet regimen (64% White, 65% Black, 83% other races, p=0.7); 48% received SCT (54% White, 28% Black, 33% other races, p<0.001).

Compared to Medicare, private insurance (adjusted odds ratio [AOR]=0.47, 95% confidence interval [CI], 0.26-0.84) and self-pay or other payors (AOR=0.16, 95% CI, 0.04-0.76) had lower odds of prescription fill for lenalidomide; Medicaid did not have significantly different odds (AOR=0.41, 95% CI, 0.17-1.02). One year increase in age (AOR=0.94, 95% CI, 0.92-0.97) and CKD (AOR=0.26, 95% CI, 0.15-0.45) were associated with lower odds of lenalidomide use. Race and treatment facility location were not associated with lenalidomide fill.

Compared to Medicare beneficiaries, those self-paying or with other payors (AOR=0.14, 95% CI, 0.03-0.53) had lower odds of any triplet regimen use; privately insured (AOR=0.65, 95% CI, 0.39-1.09) and those with Medicaid (AOR=0.65, 95% CI, 0.30-1.43) did not have significantly different odds. One unit increase in CCI (AOR=1.16, 95% CI, 1.08-1.24) and in the year of diagnosis (AOR=1.15, 95% CI, 1.01-1.30) were associated with higher odds of triplet regimen use, while a 1-year increase in age was associated with 3% lower odds (AOR=0.97, 95% CI, 0.95-0.998). Race and treatment facility location were not associated with triplet regimen use.

Compared to White individuals, Black patients had lower odds of receiving SCT (AOR=0.46, 95% CI, 0.25-0.83). One year increase in age was associated with an 11% decrease (AOR=0.89, 95% CI, 0.86-0.92) and 1 unit increase in CCI with a 13% decrease (AOR=0.87, 95% CI 0.81-0.94) in the odds of SCT, while a more recent year of diagnosis was linked to higher odds of SCT (AOR=1.30, 95% CI, 1.12-1.51). Patients treated at regional hospitals also had lower odds of SCT (AOR=0.26, 95% CI, 0.12-0.55), compared to Taussig Cancer Center and satellite family health centers. Insurance type was not associated with SCT.

Conclusions: Care for MM varies based on race, insurance type, and location of treatment facility. Strategies are needed to reduce non-preference based variations in MM treatment, including via examination of patient out-of-pocket costs, pre-authorization criteria, and other SDOH.