Age <60 60-64 65-74 75+ Age <60 60-64 65-74 75+ OR(Age) within Strata of Race OR(Race) within Strata of Age Schymura et al. BMC Cancer 2010, 10:152 http://www.biomedcentral.com/1471-2407/10/152 Page 12 of 15 Table 5: Alternate presentations of odds ratios by age and race for receipt of radiation therapy among patients receiving definitive treatment (model 1 from Table 4). Non-Black OR (95% CI) Non-Hispanic Black OR (95% CI) 1.00 1.95 7.55 69.73 1.00 1.00 1.00 1.00 referent (1.36 - 2.83) (5.57 - 10.40) (41.94 - 120.93) referent referent referent referent 1.00 0.97 1.98 16.53 2.62 1.30 0.69 0.62 referent (0.46 - 2.00) (1.08 - 3.70) (4.80 - 77.66) (1.50 - 4.52) (0.69 - 2.37) (0.44 - 1.06) (0.18 - 2.90) number of non-white and Hispanic prostate cancer patients was still relatively small and may not have allowed us to adequately assess racial and ethnic differ- ences. Furthermore, the five-year lag between cancer diagnosis and data collection resulted in difficulty retrieving some medical information. Reliance on face sheets in medical records for comorbidity information probably led to under-ascertainment of comorbidities. The study also did not have access to individual-level measures of socioeconomic status and relied instead on area-derived Census measures. This may have resulted in inadequate adjustment for socioeconomic effects. Finally, we were unable to examine cause-specific mortality in addition to overall mortality. The CDC-NPCR Patterns of Care study follows the Institute of Medicine recommendations that data systems such as SEER and NPCR be used to conduct surveillance of treatment in the United States [7]. Although a number of prostate cancer patterns of care studies have been con- ducted using data from the SEER program, this is the first such study using data from the NPCR. There is some evi- dence to suggest that patients residing in SEER areas are somewhat more affluent [53] and may have greater access to high quality cancer care. Of the seven states that par- ticipated in this study, none was part of the SEER pro- gram in 1997, and several had not participated in previous patterns of care studies (e.g., New York). For these states, this study was very significant in that it pro- vided them with valuable baseline treatment information and enhanced their capacity to conduct treatment sur- veillance. The present study also serves as the foundation for future NPCR patterns of care studies, one of which is currently in progress [54]. The second NPCR Patterns of Care study addresses several limitations of the current study. In particular, sampling was stratified by race, and more detailed treatment data are being collected, includ- ing radiation dose. Conclusions The fact that geographic variation remained even after adjusting for other factors, both in treatment patterns as well as in survival, suggests true regional differences in how physicians and patients select treatment options. Factors affecting treatment choice and treatment effec- tiveness need to be further explored in future population- based studies. Prostate cancer treatment contributes sig- nificantly to national healthcare costs because of the sheer number of men who are affected [55], with the cost per patient dependent on the type of treatment received [56]. Given the current healthcare reform discussions, a thorough understanding of the factors driving treatment selection is both critical and timely [57]. Competing interests The authors declare that they have no competing interests. This study was funded in large part through cooperative agreements awarded by the Division of Cancer Prevention and Control, Centers for Disease Control and Prevention to the states of California, Colorado, Illinois, Louisiana, New York (U58/ CCU220322), Rhode Island, and South Carolina. The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention. Authors' contributions MJS, ARK, JLF, JPF and TS contributed to the development of the PoC1 study protocol. RRG was responsible for study coordination among registries. MJS and ARK were responsible for the data analyses that are presented in this man- uscript. MJS was responsible for the drafting of the manuscript; RRG and MCH contributed significantly to the literature review; and all authors contributed to the final manuscript. All authors read and approved the final manuscript.