Abstract PD6-04: PD6-04 Baseline Insurance and Unplanned Emergency Room Use and Hospitalizations Among Elderly Breast Cancer Patients Participating in Clinical Trials
Authors: Hershman Dawn L. , Vaidya Riha , Till Cathee , Barlow William E. , LeBlanc Mike , Unger Joseph M. 
Published: March 2023

Background Reducing acute care use is an important strategy for improving value in cancer care. Patients with cancer are at risk for unplanned Emergency Room (ER) visits and hospitalizations during treatment which can increase the cost of care. Patients enrolled in clinical trials have equal access to supportive care and are treated uniformly according to protocol. While demographic factors such as age, race and number of comorbidities have been associated with increased healthcare utilization, less is known about insurance status, which may be a proxy for structural barriers to outpatient quality care, especially since many unplanned ER visits and hospitalizations are preventable. Methods We conducted a retrospective analysis among breast cancer patients over the age of 65 treated on SWOG clinical trials from 2001 to 2019 with trial data linked to Medicare claims. Patients were included if they were enrolled in Medicare for at least 12 continuous months after trial registration. Type of insurance at trial enrollment was classified as Medicare alone, Medicare + Commercial or Medicare + Medicaid. The outcomes – derived from Medicare claims – were healthcare utilization ER visits, hospital stays, and healthcare costs in the first year. Demographic, clinical, and prognostic factors were captured from clinical trial records. Logistic regression was used to examine utilization outcomes and linear regression was used to examine healthcare costs. Regression models were adjusted for age, race, and a study-specific prognostic risk score, and stratified by study and treatment. Costs were analyzed in 2021 US dollars. Results In total, N = 1,067 patients were analyzed. Median age was 70 years, 32% of patients had Medicare alone, 64% had Medicare + Commercial, and 4% had Medicare + Medicaid. Overall 29% had one or more ER visits and 22% had one or more hospital stays. There were no differences in outcomes between patients with Medicare alone vs. Medicare + Commercial; these groups were combined. In adjusted analyses, patients on Medicare + Medicaid were statistically significantly more likely to have a hospital stay or ER visit (combined outcome) within 12 months of trial registration (58% vs 34%; OR [95% CI], 2.13 [1.05-4.31], p=.04). Separately, patients on Medicare + Medicaid were statistically significantly more likely to have ER visits (51% vs 27.7%, OR [95% CI], 2.09 [1.05-4.19], p=.04), but not hospitalizations (34.9% vs 20.7%, OR [95% CI], 1.55 [0.74-3.24], p=.25) compared to the others combined. Mean costs were higher for patients who had Medicare + Medicaid compared to the others combined, but the differences were not statistically significant ($43,150 vs. $37,259, p = 0.55), possibly due to the small Medicare + Medicaid sample size. Conclusion Despite participation in a BC clinical trial, patients with Medicare + Medicaid had a two-fold increased risk of unplanned ER visits despite controlling for clinical, demographic and prognostic factors. These findings suggest that access and structural factors may adversely influence utilization outcomes for socioeconomically vulnerable older patients with breast cancer. In conjunction with reducing insurance related barriers to clinical trials, efforts are needed to ensure adequate clinical resources to prevent unplanned use of acute care.

Citation Format: Dawn L. Hershman, Riha Vaidya, Cathee Till, William E. Barlow, Mike LeBlanc, Joseph M. Unger. PD6-04 Baseline Insurance and Unplanned Emergency Room Use and Hospitalizations Among Elderly Breast Cancer Patients Participating in Clinical Trials [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD6-04.