Burden of illness of bone metastases in prostate cancer patients in Québec, Canada: A population-based analysis

Introduction: Metastasis of prostate cancer (PC) to bone (metastatic bone disease, MBD) increases morbidity, but Canadian data are lacking on the associated healthcare resource utilization (HCRU) and costs. We quantified MBD-related HCRU and associated costs in this population, and assessed skeletal-related events (SREs), such as pathologic fracture, spinal cord compression, bone radiotherapy, and bone surgery. Methods: We conducted a retrospective, population-based cohort study using the Quebec health insurance agency database. Prescription drug and medical services data were retrieved for patients with ≥1 healthcare claim in 2001 with a PC diagnosis (International Classification of Diseases, 9th Revision, Clinical Modification [ICD-9-CM] code of 185.xx). Patients with ≥2 MBDrelated claims or an SRE were compared with a matched-control group of PC patients without MBD. Patients were followed until death, loss to follow-up, or the end of available data (August 31, 2010). Costs (in 2012 Canadian dollars) were adjusted for age, year of MBD diagnosis, general health status, and baseline resource utilization. Results: Compared with controls (n = 1671), MBD patients (n = 626) had significantly higher HCRU. Adjusted mean (95% confidence interval) all-cause healthcare costs were $11 820 (7248–16 058) higher, and MBD-related costs were $3 091 (1267–4861) higher in MBD patients than in controls. Nearly 50% of MBD patients received radiotherapy within 2.5 years of their MBD diagnosis, but most exited the study without experiencing other SREs. Conclusion: MBD imposes a heavy HCRU and cost burden among patients with PC in Canada. Effective therapy is needed to reduce the clinical and economic impact of MBD in this population.