Treatment Decision Making and Financial Toxicity in Women With Metastatic Breast Cancer

Introduction: Oncologists have increasingly been proponents of shared decision making (SDM) to enhance patient outcomes and reduce unnecessary health care spending. However, its effect on patient out-of-pocket costs is unknown. This study investigated the relationship between patient preferences for SDM and financial toxicity (FT) in patients with metastatic breast cancer (MBC).

Patients and methods: This cross-sectional study utilized surveys of women aged ≥ 18 with MBC who received care at two academic hospitals in Alabama from 2017 to 2019. Patients self-reported their SDM preference (Control Preferences Scale) and FT (Comprehensive Score for Financial Toxicity [COST] tool; 11-item scale, with lower scores indicating worse FT). Effect sizes were calculated using the proportion of variance explained (R²) or Cramer's V. Differences in FT by SDM preference were estimated using mixed models clustered by site and treating medical oncologist.

Results: In 95 women with MBC, 44% preferred SDM, 29% preferred provider-driven decision making, and 27% preferred patient-driven decision making. Patients preferring SDM were more often college educated (53% vs. 39%; V = 0.12) with an income greater than $40,000/y (55% vs. 43%; V = 0.18). Overall median COST was 22 (interquartile range, 16-29). After adjusting for patient demographic and clinical characteristics, patients preferring patient-driven decision making trended toward worse FT (COST 17: 95% confidence interval, 12-22) compared to those preferring SDM (COST 19: 95% confidence interval, 15-23) and those preferring provider-driven decision making (COST 22: 95% confidence interval, 17-27).

Conclusion: Patients preferring more patient-driven decision making reported worse FT, although differences did not reach statistical significance. Further research is needed to understand this relationship.