Impact of symptomatic skeletal events on healthcare resource utilization, health-related quality of life and pain among patients with castration-resistant prostate cancer and bone metastases.

247 Background: Prostate cancer patients frequently develop bone metastases (BM), leading to symptomatic skeletal events (SSE). Given the real-world data on SSE are lacking, this study evaluated the impact of SSE on healthcare resource utilization (HRU), health-related quality of life (HRQoL), and pain in patients with castration-resistant prostate cancer (CRPC) and BM. Methods: Electronic medical records (EMR) and clinical database of a tertiary oncology center were used to identify CRPC patients with BM. SSE, including pathologic fracture, radiation to bone, spinal cord compression, and bone surgery, were extracted from medical charts. HRU, such as emergency room (ER), outpatient and inpatient visits, was determined from the EMR. A subset of patients who were alive and had clinic visits from 11/2014-7/2015 completed HRQoL (FACT-P) and pain (BPI-SF) surveys. The impact of SSE on HRU was evaluated using multivariate negative binomial regression. Survey scores were compared using Rank-Sum test and standardized effect sizes (ES); an ES ≥ 0.33 corresponds to meaningful differences between SSE and non-SSE groups. Lower FACT-P and BPI-SF scores suggest reduced HRQoL and less pain, respectively. Results: Of 832 patients, 207 developed ≥ 1 SSE (mean 1.5±0.8); 84% had radiation to bone. The median age at CRPC with BM diagnosis was 68 yrs. and follow-up after diagnosis was 2.1 yrs. Adjusting for baseline factors, the SSE group had significantly higher ER (incidence rate ratio (IRR) = 1.48; 95% confidence interval (CI) = 1.12, 1.95), outpatient (IRR = 1.17; 95% CI = 1.05, 1.30), and inpatient (IRR = 1.74; 95% CI = 1.34, 2.26) visits. Of 107 patients eligible for surveys, 103 responded. The mean FACT-P functional well-being score was 17.5 in SSE and 19.8 in non-SSE group (p = 0.16) with an ES of 0.36. Mean BPI-SF pain severity score was 2.5 in SSE and 1.6 in non-SSE group (p = 0.05) with an ES of 0.47, and that for worst pain was 3.6 and 2.3, respectively, (p = 0.03) with an ES of 0.5. Conclusions: The economic and quality of life burden of SSE amongst CRPC patients with BM is high, underscoring the need for preventive treatments for SSE in this population.