Background: Patients with BMets secondary to BC are predisposed to SREs, defined as spinal cord compression (SCC), pathologic fracture (PF), surgery to bone (SB), and radiation therapy to bone (RT). Information on health care utilization and costs to treat SRE episodes in BC patients are limited. The objective of this study was to document current patterns of healthcare utilization and costs of SRE in patients with BC and BMets. Methods: This was a retrospective, observational study using the Thomson MedStat MarketScan Commercial Claims and Encounters database from 9/2002 to 6/2011. Study subjects included all persons with claims for BC (ICD-9-CM 174.xx) and for BMets (ICD-9-CM 170.xx or 198.5x), and ≥1 claim(s) for SRE. Key inclusion criteria included no other primary cancer and continuous enrollment ≥6 mos prior to BMets diagnosis. Unique SRE episodes were identified based on a gap of ≥90 days without an SRE claim, and classified by treatment setting (inpatient [IP, hospitalized for SRE during episode] or outpatient [OP]) and SRE type (SCC; PF [and no SCC]; SB [and no SCC or PF]; RT [and no SCC, PF, or SB]). Results: Of 22,709 BC patients with BMets, 11,941 had ≥1 SRE. Among 5,809 patients who met all other criteria, there were 7,617 SRE episodes over a mean (SD) follow-up of 17.2 (15.2) mos. The percent of SRE episodes that required IP treatment ranged from 11% (RT) - 76% (SB) (23% overall). On average, IP SCC episodes were most costly; while OP PF episodes were least costly. Of the total SRE costs (mean [SD] $21,072 [$36,462]/episode), 36% were for OP RT and 31% were for IP PF. Conclusions: In patients with BC and BMets, SREs are frequent and associated with high costs and hospitalizations. OP RT and IP PF account for a large share of SRE costs. Treatments that prevent SREs in these patients may reduce these costs.

Abbreviations: IP, inpatient; OP, outpatient.