title: Physician variation in management of low-risk prostate cancer: a population-based cohort study.
abstract: OBJECTIVE
  Up-front treatment of older men with low-risk prostate cancer can cause morbidity without clear survival benefit; however, most such patients receive treatment instead of observation. The impact of physicians on the management approach is uncertain.
  
  
  OBJECTIVE
  To determine the impact of physicians on the management of low-risk prostate cancer with up-front treatment vs observation.
  
  
  METHODS
  Retrospective cohort of men 66 years and older with low-risk prostate cancer diagnosed from 2006 through 2009. Patient and tumor characteristics were obtained from the Surveillance, Epidemiology, and End Results cancer registries. The diagnosing urologist, consulting radiation oncologist, cancer-directed therapy, and comorbid medical conditions were determined from linked Medicare claims. Physician characteristics were obtained from the American Medical Association Physician Masterfile. Mixed-effects models were used to evaluate management variation and factors associated with observation.
  
  
  METHODS
  No cancer-directed therapy within 12 months of diagnosis (observation).
  
  
  RESULTS
  A total of 2145 urologists diagnosed low-risk prostate cancer in 12,068 men, of whom 80.1% received treatment and 19.9% were observed. The case-adjusted rate of observation varied widely across urologists, ranging from 4.5% to 64.2% of patients. The diagnosing urologist accounted for 16.1% of the variation in up-front treatment vs observation, whereas patient and tumor characteristics accounted for 7.9% of this variation. After adjustment for patient and tumor characteristics, urologists who treat non-low-risk prostate cancer (adjusted odds ratio [aOR], 0.71 [95% CI, 0.55-0.92]; P = .01) and graduated in earlier decades (P = .004) were less likely to manage low-risk disease with observation. Treated patients were more likely to undergo prostatectomy (aOR, 1.71 [95% CI, 1.45-2.01]; P < .001), cryotherapy (aOR, 28.2 [95% CI, 19.5-40.9]; P < .001), brachytherapy (aOR, 3.41 [95% CI, 2.96-3.93]; P < .001), or external-beam radiotherapy (aOR, 1.31 [95% CI, 1.08-1.58]; P = .005) if their urologist billed for that treatment. Case-adjusted rates of observation also varied across consulting radiation oncologists, ranging from 2.2% to 46.8% of patients.
  
  
  CONCLUSIONS
  Rates of management of low-risk prostate cancer with observation varied widely across urologists and radiation oncologists. Patients whose diagnosis was made by urologists who treated prostate cancer were more likely to receive up-front treatment and, when treated, more likely to receive a treatment that their urologist performed. Public reporting of physicians' cancer management profiles would enable informed selection of physicians to diagnose and manage prostate cancer.
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Hoffman
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jiangong
authors.initials: J
authors.lastname: Niu
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jing
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Urology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: John W
authors.initials: JW
authors.lastname: Davis
authors.affiliation: Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jeri
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Kuban
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: George H
authors.initials: GH
authors.lastname: Perkins
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Jay B
authors.initials: JB
authors.lastname: Shah
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Grace L
authors.initials: GL
authors.lastname: Smith
authors.affiliation: Department of General Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Volk
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Buchholz
authors.affiliation: Department of Health Services Research, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Sharon H
authors.initials: SH
authors.lastname: Giordano
authors.affiliation: Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Smith
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology / Q000628:therapy*; D000368:Aged; D015331:Cohort Studies; D006801:Humans; D008297:Male; D060787:Neoplasm Grading; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D011471:Prostatic Neoplasms / Q000473:pathology / Q000628:therapy*; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D018426:SEER Program; D057832:Watchful Waiting