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

Abstract

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