Appropriateness of Prostate Cancer Imaging among Veterans in a Delivery System without Incentives for Overutilization.

Objective: To determine the frequency of appropriate and inappropriate prostate cancer imaging in an integrated health care system.

Data Sources/study Setting: Veterans Health Administration Central Cancer Registry linked to VA electronic medical records and Medicare claims (2004-2008).

Study Design: We performed a retrospective cohort study of VA patients diagnosed with prostate cancer (N = 45,084). Imaging (CT, MRI, bone scan, PET) use was assessed among patients with low-risk disease, for whom guidelines recommend against advanced imaging, and among high-risk patients for whom guidelines recommend it.

Principal Findings: We found high rates of inappropriate imaging among men with low-risk prostate cancer (41 percent) and suboptimal rates of appropriate imaging among men with high-risk disease (70 percent). Veterans utilizing Medicare-reimbursed care had higher rates of inappropriate imaging [OR: 1.09 (1.03-1.16)] but not higher rates of appropriate imaging. Veterans treated in middle [OR: 0.51 (0.47-0.56)] and higher [OR: 0.50 (0.46-0.55)] volume medical centers were less likely to undergo inappropriate imaging without compromising appropriate imaging.

Conclusions: Our results highlight the overutilization of imaging, even in an integrated health care system without financial incentives encouraging provision of health care services. Paradoxically, imaging remains underutilized among high-risk patients who could potentially benefit from it most.