Geospatial disparities, health system factors, and breast cancer care quality.

Background: Despite longstanding efforts to improve breast cancer care quality, wide performance gaps persist. We sought to identify regions demonstrating meaningfully low performance and characterize health-system and health-profession factors associated with geospatial disparities.

Methods: We used the Surveillance, Epidemiology, and End Results-Medicare linked database and the Health Resources and Services Administration area health resource file to characterize performance across healthcare service areas using four metrics: diagnosis stage, chemotherapy, radiation, and endocrine therapy. We used principal component analysis to identify healthcare facility and provider characteristics associated with performance; and hierarchical multivariable modeling to attribute total variance proportionally to five domains: patient characteristics, health service area region, healthcare facility and provider characteristics, randomness, and unexplained.

Results: Among 31,571 women aged 66-79 diagnosed 2007-2013 with stage I-III breast cancer and treated with surgery, 61% had stage 1 disease, 23% received chemotherapy, 54% received radiation therapy, and 42% received endocrine therapy. Health system factors explained more variance for endocrine therapy (21%), chemotherapy (12%), and radiation therapy (12%), compared to geospatial region or patient characteristics. Health profession-factors were associated with quality for stage, radiation therapy and chemotherapy; healthcare facility-factors were associated with quality for stage, endocrine therapy, and chemotherapy. Patient characteristics explained <5% of observed variance.

Conclusions: Reassuringly, only a small number of regions demonstrated suboptimal breast cancer care. Optimal performance was associated with multidisciplinary teams and facilities with robust resources and higher volumes. Incorporating geospatial and health system factors into quality measurement efforts could foster the design of impactful quality improvement programs.