Residence in a rural setting is associated with lower five-year survival rates in patients that undergo spine surgery for breast cancer metastatic to the spine: A propensity matched analysis.

Background: Social determinants of health and access to care are associated with outcomes of spine surgery. The objective of the present study was to evaluate the association of residence in rural or urban counties with one-, two-, and five-year mortality in patients undergoing spine surgery for metastatic breast cancer to the spine. Methods: A retrospective propensity matching study of patients over a 10-year period, using data from the U.S. Surveillance, Epidemiology and End Results (SEER) database. Included patients were >18 years of age, underwent spine surgery for breast cancer metastatic to the spine between 2006 and 2015, and were enrolled in the SEER Medicare database. Propensity score through the inverse probability of treatment weighting (IPTW) was conducted to achieve covariate-adjusted results. Results: Of the 865 female patients, 800 patients resided in urban settings and 65 patients resided in rural settings. Residence in a rural setting was associated with a higher probability of residing in a county with a distress score in the mid-tier, at-risk, or distressed range compared to patients residing in an urban setting (p<.001). After propensity score matching, patients who were living in rural settings had higher probability of mortality at 5 years (HR, 3.39 [95% CI, 1.26-9.12], p=.016). Conclusions: Rural residence is an independent predictor of 5-year mortality for patients undergoing surgery for metastatic breast cancer to the spine and a possible surrogate marker for access to care. It is imperative for healthcare providers to understand the social determinants of health to develop strategies to address barriers to accessing care. Level of Evidence: III.