title: Radiation therapy after breast-conserving surgery: does hospital surgical volume matter? A population-based study in Taiwan.
abstract: OBJECTIVE
  To examine the association between hospital surgical volume and the use of radiation therapy (RT) after breast-conserving surgery (BCS) in Taiwan.
  
  
  METHODS
  We used claims data from the National Health Insurance program in Taiwan (1997-2005) in this retrospective population-based study. We identified patients with breast cancer, receipt of BCS, use of radiation, and the factors that could potentially associated with the use of RT from enrollment records, and the ICD-9 and billing codes in claims. We conducted logistic regression to examine factors associated with RT use after BCS, and performed subgroup analyses to examine whether the association differs by medical center status or hospital volumes.
  
  
  RESULTS
  Among 5,094 patients with newly diagnosed invasive breast cancer who underwent BCS, the rate of RT was significantly lower in low-volume hospitals (74% vs. 82%, p < 0.01). Patients treated in low-volume hospitals were less likely to receive RT after BCS (odds ratio = 0.72, 95% confidence interval = 0.62-0.83). In addition, patients treated after the implementation of the voluntary pay-for-performance policy in 2001 were more likely to receive RT (odds ratio = 1.23; 95% confidence interval = 1.05-1.45). Subgroup analyses indicated that the high-volume effect was limited to hospitals accredited as non-medical centers, and that the effect of the pay-for-performance policy was most pronounced among low-volume hospitals.
  
  
  CONCLUSIONS
  Using population-based data from Taiwan, our study concluded that hospital surgical volume and pay-for-performance policy are positively associated with RT use after BCS.
authors.affiliation: Section of Health Services Research, Department of Biostatistics, Division of Quantitative Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX 77230-1402, USA.
authors.forename: Chun-Ru
authors.initials: CR
authors.lastname: Chien
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Pan
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Tsai
authors.forename: Teressa
authors.initials: T
authors.lastname: Tsai
authors.forename: Ji-An
authors.initials: JA
authors.lastname: Liang
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Buchholz
authors.forename: Ya-Chen Tina
authors.initials: YC
authors.lastname: Shih
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D015412:Mastectomy, Segmental / Q000706:statistics & numerical data*; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data*; D010816:Physician Incentive Plans; D011878:Radiotherapy / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013624:Taiwan