title: Association between physician specialty and volumes of treated patients and mortality among patients hospitalized for newly diagnosed heart failure.
abstract: OBJECTIVE
  To assess the effects of hospital care by a specialist or nonspecialist physician, and by volume of treated patients, on mortality among hospitalized patients with newly diagnosed heart failure.
  
  
  METHODS
  Data describing heart failure patients in Alberta, Canada, from April 1, 1994, to March 31, 2000, were extracted from hospital abstracts and analyzed using hierarchical regression, with adjustment for patient demographic characteristics, comorbid conditions, physician volume, physician specialty, and hospital volume.
  
  
  RESULTS
  There were 16,162 hospital discharges for heart failure. Nonspecialist physicians were predominantly in the two lowest-volume quartiles (93%) and specialists were predominantly in the two highest-volume quartiles (68%). Considering the effects of volume alone and after adjustment for comorbidity, for each 10 additional hospital patients treated by a physician, the odds ratio for in-hospital mortality was 0.97 (95% confidence interval [CI]: 0.95 to 0.98), and the odds ratio for 1-year mortality was 0.99 (95% CI: 0.98 to 0.999). In analyses that considered both volume and specialty, the odds of in-hospital mortality decreased by 4% for each 10 additional in-hospital patients treated by a physician (odds ratio [OR] = 0.96; 95% CI: 0.95 to 0.98). In these same analyses, the odds ratio for in-hospital mortality was 1.32 (95% CI: 1.13 to 1.53) for general practitioners with specialist consultation and 1.32 (95% CI: 1.08 to 1.61) for specialists compared with general practitioners without specialist consultations. At 1 year, mortality was not associated significantly with the volume of in-hospital patients treated, or with the specialty of the treating physician.
  
  
  CONCLUSIONS
  Treatment by high-volume physicians during hospitalization for newly diagnosed heart failure was associated with a decrease in mortality, but these benefits did not persist at 1 year. The increased mortality noted in patients treated by specialists may be due to residual confounding or unmeasured comorbidity.
authors.affiliation: Department of Medicine, University of Alberta, Canada. Bibiana.Cujec@ualberta.ca
authors.forename: Bibiana
authors.initials: B
authors.lastname: Cujec
authors.forename: Hude
authors.initials: H
authors.lastname: Quan
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.forename: David
authors.initials: D
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002170:Canada / Q000453:epidemiology; D002309:Cardiology / Q000706:statistics & numerical data*; D016001:Confidence Intervals; D003953:Diagnosis-Related Groups; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000401:mortality*; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007297:Inpatients / Q000706:statistics & numerical data*; D008297:Male; D008511:Medicine / Q000706:statistics & numerical data; D008875:Middle Aged; D016017:Odds Ratio; D010343:Patient Admission; D012720:Severity of Illness Index; D013038:Specialization