Economic burden of skeletal-related events in patients with multiple myeloma: analysis of US commercial claims database.

AIMS: To estimate incremental healthcare resource utilization (HRU) and costs associated with skeletal-related events (SREs) secondary to multiple myeloma (MM), and HRU and cost differences in patients with one vs multiple SREs.

METHODS: Adults with MM diagnosis between January 1, 2010-December 31, 2014, with benefits coverage ≥12 months pre- and ≥6 months post-diagnosis were followed to last coverage date or December 31, 2015, excluding patients with prior anti-myeloma treatment or cancers. SREs were identified by diagnosis or procedure codes (pathological fracture, spinal cord compression, radiation, or surgery to the bone). SRE patients (index = first post-diagnosis SRE) were propensity score matched 1:1 to patients without SRE (assigned pseudo-index) using baseline characteristics, and ≥1 month of continuous enrollment after index/pseudo-index date was required. Per-patient-per year (PPPY) HRU and costs (2016 US$) were determined for inpatient, outpatient, emergency department (ED), and outpatient pharmacy services during follow-up. Wilcoxon signed rank for means and McNemar's tests for proportions were used to assess differences. Negative binomial regression and generalized linear regression analyses estimated differences in HRU and costs, respectively, for the comparison of single vs multiple SREs.

RESULTS: Each cohort included 848 patients (mean age = 61 - 62 years, 57% male) with no significant differences in pre-index demographic or clinical characteristics between matched cohorts. Versus non-SRE patients, SRE patients had significantly higher PPPY use (p < .0001) of inpatient hospitalizations, ED visits, outpatient pharmacy, and higher direct medical costs ($188,723 vs $108,160, p < .0001). Adjusted PPPY total costs were $209,820 in patients with multiple SREs; $159,797 in patients with one SRE.

LIMITATIONS: SRE misclassification and residual confounding are possible.

CONCLUSIONS: Among patients with MM, average annual costs were substantially higher in patients with SRE compared with matched non-SRE patients. The economic burden of SRE increased further with multiple events.