Disparities in clinical trial participation among older adult Medicare beneficiaries with hematologic malignancies from 2006 to 2019: A SEER-Medicare analysis.

[BACKGROUND] Clinical trials (CTs) are essential for expanding treatment options across hematologic malignancies (HM) and providing access to novel treatments. However, older adults with HM are often underrepresented in CTs, and a national-level evaluation of factors influencing their participation is lacking.

[METHODS] The authors conducted a retrospective cohort study using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database, identifying patients ≥66 years old diagnosed with HM between 2006 and 2018 (follow-up to December 2019). CT participation was defined by Medicare claims for CT services. Cumulative incidence and Fine-Gray models were used to estimate participation rates and adjusted hazard ratios (aHRs) assessed the association between participation and sociodemographic factors.

[RESULTS] The cohort (n = 53,919) was 50% female, median age 78 years old, and 86% White. Cumulative incidence of CT participation was low at 2.7% at 1 year after diagnosis, increasing to 4.3% at 5 years. After adjustment for the competing risk of death, significantly lower CT participation was observed for older age (vs. 66-69 years: aHR for 70-74 years, 0.79 [95% CI, 0.71-0.88]; aHR for 75-79 years, 0.63 [95% CI, 0.56-0.70]; aHR for 80-84 years, 0.41 [95% CI, 0.36-0.46]; aHR for ≥85 years, 0.21 [95% CI, 0.18-0.24]), female sex (aHR, 0.79 [95% CI, 0.73-0.86]), Black race (aHR, 0.73 [95% CI, 0.59-0.90]), certain comorbidities (aHR for pulmonary disease, 0.76 [95% CI, 0.68-0.85]; aHR for renal disease, 0.67 [95% CI, 0.59-0.76]), dual Medicare-Medicaid eligibility (aHR, 0.66 [95% CI, 0.56-0.77]), and distance to National Cancer Institute centers from the patient's ZIP code (aHR for ≥250 miles, 0.64 [95% CI, 0.48-0.86]).

[CONCLUSIONS] These results highlight the need for targeted interventions, such as CT navigator programs and decentralized trials, to increase older adult participation in HM CTs.