Clinical research studies
Association between physician specialty and volumes of treated patients and mortality among patients hospitalized for newly diagnosed heart failure

https://doi.org/10.1016/j.amjmed.2004.08.013Get rights and content

Purpose

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 to1.53) 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.

Conclusion

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.

Section snippets

Methods

The analysis was done within the protected environment of Alberta Health and Wellness and was governed by section 27 of the Alberta Health Information Act on the use of health data in the custodial care of the provincial government. This study was exempted from informed patient consent or ethical board review by meeting the requirement for physician practice surveillance and quality assurance.

For this study we used the following administrative data sources: Canadian Institute for Health

Results

During the 6 years of the study, the 16,162 patients who had acute care hospital discharges for newly diagnosed heart failure constituted 50% of the 32,139 total admissions for heart failure. In-hospital mortality for newly diagnosed heart failure was 9%, and overall 1-year mortality was 23%. The median number of heart failure patients per unique most responsible physician was 34. General practice physicians without a specialist/subspecialist consultation treated 46% of patients, general

Discussion

We found that hospital management of heart failure patients by high-volume physicians was associated with improved in-hospital survival. After adjusting for hospital volume and comorbid conditions, the odds of in-hospital mortality among heart failure patients decreased with volume of patients treated. This association persisted even after accounting for physician specialty. However, the mortality benefits of high-volume physician care during actual hospitalization did not persist at 1 year.

References (56)

  • D.W. Baker et al.

    Variations in family physicians’ and cardiologists’ care for patients with heart failure

    Am Heart J

    (1999)
  • R.A. Deyo et al.

    Adapting a clinical comorbidity index for use with ICD-9-CM administrative databases

    J Clin Epidemiol

    (1992)
  • P.S. Romano et al.

    Adapting a clinical comorbidity index for use with ICD-9-CM administrative datadiffering perspectives

    J Clin Epidemiol

    (1993)
  • L.I. Iezzoni

    Using risk-adjusted outcomes to assess clinical practicean overview of issues pertaining to risk adjustment

    Ann Thorac Surg

    (1994)
  • P. Shackley et al.

    Is there a positive volume–outcome relationship in peripheral vascular surgery? Results of a systematic review

    Eur J Vasc Endovasc Surg

    (2000)
  • M. Simunovic et al.

    Hospital procedure volume and teaching status do not influence treatment and outcome measures of rectal cancer surgery in a large general population

    J Gastrointest Surg

    (2000)
  • C. Maynard et al.

    Outcome of coronary angioplasty procedures performed in rural hospitals

    Am J Med

    (2000)
  • T.A. Gordon et al.

    Complex gastrointestinal surgeryimpact of provider experience on clinical and economic outcomes

    J Am Coll Surg

    (1999)
  • K.O. Akosah et al.

    Chronic heart failure in the communitymissed diagnosis and missed opportunities

    J Card Fail

    (2001)
  • D.R. Murdoch et al.

    Importance of heart failure as a cause of death. Changing contribution to overall mortality and coronary heart disease mortality in Scotland 1979–1992

    Eur Heart J

    (1998)
  • T. Ryden-Bergsten et al.

    The health care costs of heart failure in Sweden

    J Intern Med

    (1999)
  • M. Mejhert et al.

    Epidemiology of heart failure in Sweden—a national survey

    Eur J Heart Fail

    (2001)
  • A. Owen et al.

    Diagnosis of heart failure in elderly patients in primary care

    Eur J Heart Fail

    (2001)
  • S. Stewart et al.

    Trends in hospitalization for heart failure in Scotland, 1990-1996. An epidemic that has reached its peak?

    Eur Heart J

    (2001)
  • J.B. Croft et al.

    Heart failure survival among older adults in the United Statesa poor prognosis for an emerging epidemic in the Medicare population

    Arch Intern Med

    (1999)
  • J. Herlitz et al.

    Mode and risk indicators for death during 5 year follow-up of survivors of acute myocardial infarction. An evaluation with particular emphasis on congestive heart failure and age

    Coron Artery Dis

    (1997)
  • C.M. Ashton et al.

    Rates of health services utilization and survival in patients with heart failure in the Department of Veterans Affairs medical care system

    Am J Med Qual

    (1999)
  • C.A. Polanczyk et al.

    Ten-year trends in hospital care for congestive heart failureimproved outcomes and increased use of resources

    Arch Intern Med

    (2000)
  • Cited by (13)

    • Determinants of early readmission after hospitalization for heart failure

      2014, Canadian Journal of Cardiology
      Citation Excerpt :

      Those transferred in from other facilities may have been more likely to live in rural settings with less access to outpatient follow-up or specialty HF services after hospitalization, as described in other studies.25,26 Using 1994-2000 Alberta administrative data, Cujec et al. reported that patients with HF cared for by primary care physicians were less likely to be readmitted within 180 days after discharge (adjusted odds ratio [aOR], 0.81; 95% confidence interval [CI], 0.71-0.92) compared with specialist-treated patients.27 Our more recent data show that although specialty of the attending physician was not associated with readmission risk after adjustment for comorbidity burdens and patient demographics, patients discharged from hospitals with specialized HF services were at lower risk for readmission regardless of duration of observation (ie, 7 days and 30 days) or reason for readmission (ie, all causes or HF).

    • Predictors of hospital length of stay in heart failure: Findings from get with the guidelines

      2011, Journal of Cardiac Failure
      Citation Excerpt :

      Hospital volume is now considered a surrogate of quality and has been incorporated into hospital referral criteria for high-risk procedures.9,10 When volume per provider was previously evaluated, inpatient mortality decreased by 4% for each 10 additional HF patients cared for by a provider (OR = 0.96; 95% CI: 0.95 to 0.98); there was, however, no significant difference in LOS, readmission rate, or long-term (1 year) survival by volume quartile.11 As noted in this study and a previous analysis of 36,078 patients enrolled in the GWTG-HF program,12 longer LOS did correlate with a greater percentage of overall core quality measures being achieved.

    • Bayesian gamma frailty proportional hazard model using spline for hazard function

      2017, International Journal of Agricultural and Statistical Sciences
    View all citing articles on Scopus

    This work was partially supported by the Alberta Center for Health Service Utilization Research. The opinions and conclusions expressed in this paper are those of the authors, and no endorsement by the Alberta Ministry of Health & Wellness is implied.

    View full text