(B-125) Contact with the Health Care System Among Older Adults with HER2-Positive Metastatic Breast Cancer

Background: Older adults diagnosed with metastatic cancer spend between 10% and 25% of their time in contact with the health care system. Understanding the frequency of health care contact days associated with a cancer diagnosis and subsequent treatment is necessary to make informed, shared decisions regarding care.

Objectives: To compare health care contact days between older adults with HER2-postive metastatic breast cancer who were and were not treated with a trastuzumab-containing regimen.

Methods: In this cohort study, we used the SEER-Medicare linked database to identify older adults (>65 years old) who were diagnosed with HER2-positive metastatic breast cancer from 2010 to 2019 and were continuously enrolled in fee-for-service Medicare Parts A and B in the 12 months before and 1 month after diagnosis. In the 12 months following diagnosis, we identified days spent in institutional (hospital, emergency department, skilled nursing facility, and inpatient hospice) and ambulatory (visits, tests, imaging, procedures, and treatment) care settings. Health care contact days were identified until Medicare disenrollment, death, or study end. We used descriptive statistics to compare health care contact days (e.g., total and type of encounters) between beneficiaries who did and did not receive a trastuzumab-containing regimen within 12 months of diagnosis.

Results: Among the 1,509 beneficiaries studied, 58.58% were treated with a trastuzumab-containing regimen in the 12 months following diagnosis. Beneficiaries who were treated had significantly higher contact with the health care system (mean: 66.93 days, SD: 39.63 days) compared with their counterparts who were not treated (mean: 26.30 days, SD: 38.12 days; p< 0.0001). Among the treated population, contact days were driven by ambulatory care (mean: 49.75 days, SD: 31.67 days), specifically visits with health care providers (mean: 24.07 days, SD: 14.55 days) and the receipt of treatment (mean: 30.35 days, SD: 22.68 days). Conversely, institutional care (mean: 15.00 days, SD: 28.04 days), primarily hospitalizations (mean: 6.39 days, SD: 13.97 days) and skilled nursing facility stays (mean: 6.82 days, SD: 18.70 days), was the driver of contact with the health care system in the untreated cohort.

Conclusions: Although treatment with a trastuzumab-containing regimen is the standard of care for HER2-positive metastatic breast cancer, 41.42% of beneficiaries did not receive treatment, which in turn, likely impacted the frequency of care in the institutional setting and the low intensity of health care contact days overall. Future research is needed to understand patients’ preferences for treatment and the quality of life associated with health care contact days.