Background: The Medicare Modernization Act led to moderate reductions in reimbursement for androgen-deprivation therapy (ADT) for prostate cancer, starting in 2004 and followed by substantial changes in 2005. We hypothesized that these reductions would lead to decreases in the use of ADT for indications that were not evidence based.
Methods: Using the Surveillance, Epidemiology, and End Results (SEER) Medicare database, we identified 54,925 men who received a diagnosis of incident prostate cancer from 2003 through 2005. We divided these men into groups according to the strength of the indication for ADT use. The use of ADT was deemed to be inappropriate as primary therapy for men with localized cancers of a low-to-moderate grade (for whom a survival benefit of such therapy was improbable), appropriate as adjuvant therapy with radiation therapy for men with locally advanced cancers (for whom a survival benefit was established), and discretionary for men receiving either primary or adjuvant therapy for localized but high-grade tumors. The proportion of men receiving ADT was calculated according to the year of diagnosis for each group. We used modified Poisson regression models to calculate the effect of the year of diagnosis on the use of ADT.
Results: The rate of inappropriate use of ADT declined substantially during the study period, from 38.7% in 2003 to 30.6% in 2004 to 25.7% in 2005 (odds ratio for ADT use in 2005 vs. 2003, 0.72; 95% confidence interval [CI], 0.65 to 0.79). There was no decrease in the appropriate use of adjuvant ADT (odds ratio, 1.01; 95% CI, 0.86 to 1.19). In cases involving discretionary use, there was a significant decline in use in 2005 but not in 2004.
Conclusions: Changes in the Medicare reimbursement policy in 2004 and 2005 were associated with reductions in ADT use, particularly among men for whom the benefits of such therapy were unclear. (Funded by the American Cancer Society.).