Demographics, Medical Comorbidities, and Functional Factors Associated with Radiation Therapy Regimen Length in Older Patients

Abstract

To determine demographic, comorbidity, and functional factors associated with radiation therapy (RT) regimen length in older patients. Using data from the Medicare Current Beneficiary Survey (MCBS), we identified patients who were diagnosed with cancer from 2002-2019 and received RT. The MCBS dataset is comprised of linked patient survey and Medicare claims data. Days of RT were used as a proxy for fractions of RT each patient received. We used treatment guidelines to identify a minimum treatment threshold for each cancer type to differentiate patients with low RT utilization from normal or supra-palliative RT utilization. Statistical analyses of patient demographics, comorbidities, and activities of daily living (ADL) were performed using chi-square and t-tests. A total of 880 patients were included in this analysis, of whom 669 had high RT utilization. Of the demographic factors considered, age 85+ was associated with longer RT regimen length (p = 0.045), as was being "other" or multi-race, community, or facility treatment setting, and residing in the south (p = 0.013, 0.006, 0.003, 0.038, respectively). Of medical comorbidities, only lung disease was associated with longer RT regime (p = 0.020). Longer RT regimen length was significantly associated with requiring assistance with any ADLs (bathing, dressing, eating, chair, walking, toileting, all with p <0.001). This abstract identifies specific patient demographics, medical comorbidities, and ADL limitations which may be associated with RT regimen length in older patients. Future work should focus on optimizing patients and delivery systems for RT and the relationship between pre- and post-treatment ADLs.