title: Understanding regional variation in Medicare expenditures for initial episodes of prostate cancer care.
abstract: OBJECTIVE
  To evaluate the contributions of patient and treatment factors to overall expenditures and regional variation for initial treatment of localized prostate cancer (CaP) in the Medicare program.
  
  
  METHODS
  Using the Surveillance, Epidemiology, and End Results-Medicare database, we identified 47,517 beneficiaries with localized CaP during 2005-2009 and matched noncancer controls. We employed hierarchical generalized linear models to estimate risk-standardized cancer-related expenditures for each hospital referral region. To identify key contributors to the variation, we sequentially added patient characteristics, treatment intensity (the percentage of patients receiving curative treatments), ancillary procedures (biopsy, hormone therapy, and imaging), and specific treatment modalities into the model. We categorized the expenditures according to the type of services to identify their relative impact on the expenditure variations.
  
  
  RESULTS
  The mean expenditure on CaP-related care per CaP beneficiary was $15,900, including $1800 on surgery, $11,200 on radiotherapy, and $1900 on ancillary procedures. The expenditure difference between quintiles 5 and 1 was $6200. Patient characteristics explained 8.4% of this difference. Treatment intensity and treatment modalities accounted for an additional 21.2% and 31.2% of the variation, respectively. Between the highest and lowest expenditure quintiles, the difference in radiotherapy expenditure was $5000, whereas that in surgery or ancillary procedures was <$200.
  
  
  CONCLUSIONS
  There is substantial geographic variation in CaP expenditures, and the specific modality of radiotherapy is the most important contributor to this variation. Efforts to address the CaP care costs, such as bundled payment development, require targeting both treatment intensity and use of costly modalities.
authors.affiliation: *Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Cancer Center, Yale University School of Medicine †Department of Chronic Disease Epidemiology, Yale School of Public Health Departments of ‡Therapeutic Radiology §Obstetrics, Gynecology, and Reproductive Sciences ∥Urology ¶Section of General Internal Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT.
authors.forename: Shi-Yi
authors.initials: SY
authors.lastname: Wang
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: James B
authors.initials: JB
authors.lastname: Yu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Ma
authors.forename: Xiao
authors.initials: X
authors.lastname: Xu
authors.forename: Simon P
authors.initials: SP
authors.lastname: Kim
authors.forename: Pamela R
authors.initials: PR
authors.lastname: Soulos
authors.forename: Avantika
authors.initials: A
authors.lastname: Saraf
authors.forename: Cary P
authors.initials: CP
authors.lastname: Gross
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D006278:Medicare / Q000191:economics*; D009367:Neoplasm Staging; D017430:Prostate-Specific Antigen; D011471:Prostatic Neoplasms / Q000191:economics* / Q000628:therapy*; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D018426:SEER Program; D012959:Socioeconomic Factors; D014481:United States
chemical_list: D017430:Prostate-Specific Antigen