Functional status and therapy receipt among older adults with multiple myeloma.
Authors: Jensen Christopher Edward , Kuo Tzy-Mey , LeBlanc Matthew Roger , Baggett Christopher D , Duchesneau Emilie Danielle , Zhou Xi , Reeder-Hayes Katherine Elizabeth , Lund Jennifer Leigh 
Published: June 2023

e18770 Background: Multiple myeloma (MM) disproportionately affects older adults, among whom aging-related impairments in activities of daily living (ADLs) are common. We aimed to evaluate the association between functional disability and receipt of myeloma therapy in a population of older MM patients who had received home health (HH) services in the year prior to MM diagnosis. Methods: We identified a cohort of adults age ≥66 diagnosed with MM from 2010-2017 who received HH services prior to diagnosis from the Surveillance, Epidemiology, and End Results (SEER) database linked to Medicare claims and the Outcome and Assessment Information Set (OASIS). OASIS captures functional assessments for Medicare beneficiaries receiving HH. Continuous Medicare enrollment for 12 months before and after cancer diagnosis was required. Primary exposure was disability, a composite score of OASIS ADL items, categorized by distributional breakpoints as mild (0-9), moderate (10-25) or severe (26-40). Primary outcome was receipt of MM therapy in the year following diagnosis. Secondary outcomes were treatment type (triplet therapy, stem cell transplant) and healthcare utilization (emergency department [ED] visits, hospitalizations). Associations between disability and outcomes were assessed via hazard ratios, adjusted for age, sex, race, comorbidity, and SEER region with death as a competing risk. For utilization outcomes, we examined differences in mean cumulative counts (MCC) for each event between disability strata. Results: Among 4,108 adults, those with severe disability were less likely to receive MM therapy (vs mild, HR = 0.70 (95% CI: 0.56-0.88); vs. moderate, HR = 0.63 (0.51-0.79). Individuals with moderate disability were more likely to receive treatment than those with mild disability (HR = 1.10 (1.02, 1.20)). Individuals with severe disability were less likely to receive triplet therapy (vs. mild, HR = 0.57 (0.35, 0.93)). Rates of triplet therapy did not differ significantly between moderate and mild disability groups (HR = 1.11 (0.94, 1.32)). Transplant was rare in all groups ( < 5%). Individuals with mild disability had fewer ED visits (MCC difference vs. moderate = -0.34 (-0.50, -0.18); vs. severe = -0.57 (-1.05, -0.10)) and fewer hospitalizations (MCC difference vs. moderate = -0.42 (-0.54, -0.30); vs. severe = -0.59 (-0.93, -0.26)) in the year following diagnosis. Both measures did not differ significantly between moderate and severe groups. Conclusions: In this large, nationwide study of older adults with MM and HH use, we identified differences in treatment receipt and healthcare utilization by degree of pre-diagnosis functional disability. Individuals with moderate disability had comparable or more treatment than those with mild disability, though they were similar to the severe group in healthcare utilization. Individuals with moderate disability receiving HH may need supportive care resources when initiating therapy.