Bone health practices in men on androgen deprivation therapy (ADT): A population-based analysis of 25,802 patients

Abstract

9631 Background: ADT is used in up to 1 in 2 men with prostate cancer. Osteoporosis and fragility fractures are important side effects of ADT. Guidelines recommend 2 important bone health practices for men on ADT - measurement of bone mineral density with dual x-ray absorptiometry (DEXA) and use of bisphosphonates in men at risk of osteoporosis. The implementation of these guidelines in practice is not well known. Methods: Using linked administrative databases, we identified 25,802 men (mean age 75.9 y, range 66–100 y) with prostate cancer who were treated with at least 6 months of ADT or who underwent bilateral orchiectomy in Ontario, Canada between 1995 and 2005. Performance of DEXA and prescription of bisphosphonates were captured using specific procedure codes and drug identification numbers, respectively. Prior use of DEXA and bisphosphonates, as well as prior diagnoses of osteoporosis and fragility fracture, were captured with specific diagnostic codes and a 3 y look-back period. Annual rates per 100 person-years were determined for both outcomes. Results: Among 25,802 men, 3.09% had a DEXA more than one year prior to starting ADT, and 3.14% had a prior diagnosis of osteoporosis. Within 2 years of starting ADT, the rate of undergoing DEXA rose from 0.50 per 100 person-years in 1995 to 19.47 in 2005. Rates of DEXA testing were higher among those with a prior diagnosis of osteoporosis, prior DEXA test, or prior fragility fracture but did not reach rates above 50 per 100 person-years in any of these groups. Bisphosphonate use increased from 0.27 per 100 person-years in 1995 to 3.18 in 2005 among prior non-users. More men on ADT were started on a bisphosphonate in the third year after starting ADT as compared to the second year, and rates were higher in year 2 than year 1. Less than one-third of men starting a bisphosphonate underwent any DEXA testing within 12 months of bisphosphonate initiation. Conclusions: Rates of DEXA testing and bisphosphonate use have increased over time among older men starting ADT, but significant gaps and delays remain in the quality of bone health care in this population. No significant financial relationships to disclose.