Low rates of bone mineral density measurement in Medicare beneficiaries with prostate cancer initiating androgen deprivation therapy

Background: Men with prostate cancer who undergo androgen deprivation therapy (ADT) are at risk for bone loss and fractures. Our objective was to determine if Medicare beneficiaries with prostate cancer in the state of Texas underwent DXA scans when initiating ADT. Methods: We identified men diagnosed with prostate cancer between 2005 and 2007 in the Texas Cancer Registry/Medicare linked database, and who received parenteral ADT or orchiectomy. We identified DXA claims within 1 year before or 6 months after starting ADT. We examined use of bone conservation agents in the subgroup of patients enrolled in Medicare Part D. Multivariate logistic regression models were used to examine determinants of DXA use. Results: The analysis included 2,290 men (2,262 parenteral ADT, 28 orchiectomy); 197 (8.6%) underwent DXA within 1 year before and 6 months after starting ADT. Men aged 75 years or older were more likely to undergo DXA than men aged 66-74 years (OR 1.5; 95% CI 1.1-2.1). Those living in small urban areas were less likely to undergo DXA than those in big areas (OR 0.40; 95% CI 0.19-0.82). Of the 1,060 men enrolled in Medicare part D, 59 (5.6%) received bone conservation agents when starting ADT; 134 (12.6%) either received bone conservation agents or underwent DXA. Conclusions: Fewer than one in ten Medicare beneficiaries with prostate cancer initiating ADT underwent a DXA exam. Variation in utilization was also related to residence area size. Further research is needed to identify whether the use of DXA in patients with prostate cancer receiving ADT will result in fracture prevention.