Racial variation in the clinical and economic burden of skeletal-related events among elderly men with stage IV metastatic prostate cancer

Abstract

Prostate cancer (PCa) outcomes vary widely among African American (AA) and non-Hispanic White (NHW) men. The authors investigated racial variation in the incidence of skeletal-related events (SREs) and SRE-related healthcare costs among AA and NHW men, a topic that has received limited attention in the literature. AA and NHW men diagnosed with metastatic PCa were identified from the linked Surveillance, Epidemiology and End Results–Medicare dataset. The sample included 6455 men with metastatic PCa, including 5420 NHW men and 1035 AA men. Approximately 16% experienced SREs during follow-up. AA men were less likely to experience SREs compared with NHW men, controlling for individual characteristics (adjusted odds ratio: 0.79; 95% CI: 0.66– 0.94). The SRE-specific costs were US$35,725 (US$22,190–US$49,260) among AA men and US$25,896 (US$21,669–US$30,123) among NHW men. Although AA men were less likely to experience SREs, there were substantial costs attributable to the treatment of SREs among AA men.

Keywords:

• African American
• health services utilization costs
• Medicare
• non-Hispanic White
• race disparities
• skeletal-related events
• stage IV metastatic prostate cancer
• surveillance, epidemiology and end results

Acknowledgements

The authors thank the staff from Pharmaceutical Research Computing for programming assistance on the primary datasets and S Verga for assistance in conducting the review of articles. The collection of the California cancer incidence data used in this study was supported by the California Department of Public Health as part of the statewide cancer reporting program mandated by California Health and Safety Code Section 103885; the National Cancer Institute's Surveillance, Epidemiology and End Results Program under contract N01-PC-35136 awarded to the Northern California Cancer Center, contract N01-PC-35139 awarded to the University of Southern California and contract N02-PC-15105 awarded to the Public Health Institute; and the Centers for Disease Control and Prevention's National Program of Cancer Registries, under agreement #U55/CCR921930-02 awarded to the Public Health Institute. The ideas and opinions expressed herein are those of the author(s), and endorsement by the State of California, Department of Public Health, the National Cancer Institute and the Centers for Disease Control and Prevention or their Contractors and Subcontractors is not intended nor should be inferred. The authors acknowledge the efforts of the Applied Research Program, National Cancer Institute; the Office of Research, Development and Information, Centers for Medicare & Medicaid Services; Information Management Services (IMS), Inc.; and the Surveillance, Epidemiology, and End Results (SEER) Program tumor registries in the creation of the SEER–Medicare database.

Financial & competing interests disclosure

Funding for shared resources (data) used in this research was provided by Bayer Healthcare Pharmaceuticals. E Onukwugha declares consulting income or grant funding from Bayer, Novartis, Janssen Analytics, Pfizer, Sanofi-Aventis and Amgen. K Bikov has received research funding from Bayer. A Hussain has received research funding for related work from Amgen and Bayer and was partly supported by a research award from the Department of Veterans Affairs. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Key issues

• The likelihood of experiencing skeletal-related events (SREs) (i.e., pathological fracture, bone surgery or spinal cord compression) in advanced prostate cancer (PCa) was 27% higher among non-Hispanic White (NHW) men compared with African American (AA) men, specifically due to the higher likelihood pathologic fracture and bone surgery events among NHW men.

• The average annual unadjusted post-SRE healthcare utilization cost was US$47,880 (95% CI: US$44,836–US$50,925) among older stage IV (M1) PCa patients with SREs.

• The unadjusted post-SRE healthcare utilization costs were US$59,134 (95% CI: US$48,294–US$ 69,973) among AA men, and US$46,171 (95% CI: US$43,080–US$49,263) among NHW men. The unadjusted post-SRE healthcare utilization costs among AA men were US$12,962 (95% CI: US$3995–US$21,930; p < 0.01) higher compared with NHW men.

• The average annual adjusted SRE-specific healthcare utilization cost attributable to the treatment of SREs was US$27,176 (95% CI: US$23,094–US$31,259) among AA and NHW men with stage IV metastatic PCa.

• The adjusted SRE-specific healthcare utilization costs were US$35,725 (95% CI: US$22,190–US$49,260) among AA men and US$25,896 (95%CI: US$21,669–US$30,123) among NHW men. However, the SRE-specific cost differences between AA and NHW men were not statistically significant.

• SRE-specific costs in AA and NHW patients were largely driven by inpatient costs.

• SRE-specific costs among older stage IV (M1) PCa patients varied by race and SRE subcomponents. Overall, bone surgery remained the most expensive SRE subcomponent.

• The current study highlights the need for further research with larger, racially diverse samples.