title: Provider case volume and outcomes following prostate brachytherapy.
abstract: OBJECTIVE
  We assessed the relationship between provider volume and outcomes following brachytherapy in a population based cohort of men.
  
  
  METHODS
  We analyzed the claims of Medicare enrolled men older than 65 years living in Surveillance, Epidemiology and End Results surveillance areas who were diagnosed with prostate cancer from 1991 to 1999 and underwent brachytherapy as initial treatment. Case volume was calculated for each physician and hospital from 1991 to 2001 from Medicare claims. Outcomes of interest were recurrence, prostate cancer death, all deaths and 2-year complications. Analyses were adjusted by patient and treatment characteristics.
  
  
  RESULTS
  We identified 5,595 men for whom a radiation oncologist and a hospital provider could be identified. Men who were older, nonwhite, lower income, unmarried, living in nonurban areas or had more comorbidities were more likely to see lower volume physicians. Physician volume was not associated with the complication rate after brachytherapy. However, men treated at higher volume hospitals had a slightly lower rate of combined complication diagnoses and procedures (OR 0.94/100 cases, p <0.01). Patients treated by higher volume physicians had a lower recurrence rate (HR 0.89/100 cases, p = 0.01) and rate of prostate cancer death (HR 0.80/100 cases, p = 0.03) with a borderline significant decrease in all deaths (HR 0.95/100 cases, p = 0.05). There was no significant association between hospital volume and recurrence, prostate cancer death or all deaths.
  
  
  CONCLUSIONS
  Men treated with brachytherapy by higher volume physicians were at lower risk for recurrence and prostate cancer death, and showed a borderline decrease in total deaths. We did not observe a clear relationship between provider volume and complications following treatment.
authors.affiliation: Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women's Hospital, Boston, Massachusetts, USA.
authors.forename: Aileen B
authors.initials: AB
authors.lastname: Chen
authors.forename: Anthony V
authors.initials: AV
authors.lastname: D'Amico
authors.forename: Bridget A
authors.initials: BA
authors.lastname: Neville
authors.forename: Ewout W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: Craig C
authors.initials: CC
authors.lastname: Earle
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000706:statistics & numerical data*; D002983:Clinical Competence; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D016896:Treatment Outcome