OBJECTIVES To determine the rate of prostate-specific antigen (PSA) screening in men aged 80 and older in Medicare and to examine geographic variation in screening rates across the U.S. DESIGN Retrospective cohort study of variation across hospital referral regions using administrative data. SETTING National random sample in fee-for-service Medicare. PARTICIPANTS Medicare beneficiaries aged 80 and older in 2003. MEASUREMENTS Percentage of men aged 80 and older screened using the PSA test. RESULTS The national rate of PSA screening in men aged 80 and older was 17.2%, but there was wide variation across regions (< 2-38%). Higher PSA screening in a region was positively associated with greater total costs (correlation coefficient (r)=0.49, P <.001), greater intensive care unit use at the end of life (r=0.46, P <.001), and greater number of unique physicians seen (r=0.36, P <.001). PSA screening was negatively associated with proportion of beneficiaries using a primary care physician as opposed to a medical subspecialist for the predominance of ambulatory care (r=-0.38, P <.001). CONCLUSION PSA screening in men aged 80 and older is common practice, although its frequency is highly variable across the United States. Its association with fragmented physician care and aggressive end-of-life care may reflect less reliance on primary care and consequent difficulty informing patients of the potential harms and low likelihood of benefit of this procedure.
