Processes and Outcomes of Care for Diabetic Acute Myocardial Infarction Patients in Ontario

Do physicians undertreat?

  1. David A. Alter, MD, PHD, FRCPC123,
  2. Yaariv Khaykin, MD, PHD, FRCPC12,
  3. Peter C. Austin, PHD1,
  4. Jack V. Tu, MD, PHD, FRCPC13467 and
  5. Janet E. Hux, MD, MSC, FRCPC13457
  1. 1Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
  2. 2Division of Cardiology, Schulich Heart Centre, Sunnybrook and Women’s College Health Sciences Centre and the University of Toronto, Toronto, Ontario, Canada
  3. 3University of Toronto Clinical Epidemiology and Health Care Research Program (Sunnybrook and Women’s College site), Toronto, Ontario, Canada
  4. 4Division of General Internal Medicine, Sunnybrook and Women’s College Health Sciences Centre and the University of Toronto, Toronto, Ontario, Canada
  5. 5Division of Endocrinology, Sunnybrook and Women’s College Health Sciences Centre and the University of Toronto, Toronto, Ontario, Canada
  6. 6Department of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada
  7. 7Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada


    OBJECTIVE—To compare the health service utilization and long-term outcomes of acute myocardial infarction (AMI) patients with and without diabetes in Ontario.

    RESEARCH DESIGN AND METHODS—We examined 25,697 patients from Ontario (6,052 and 19,645 patients with and without diabetes, respectively) who were hospitalized because of AMI between 1 April 1992 and 31 December 1993. Using linked administrative databases, we determined the use of invasive cardiac procedures at 1 year as well as the intensity of specialty follow-up care and use of evidence-based pharmacotherapies (among elderly individuals) within the first 90 days of hospital discharge. Outcomes examined included mortality and recurrent cardiac admissions at 30 days and 5 years post AMI. Multivariable analyses adjusted for sociodemographic and case-mix characteristics, attending physician specialty, and admitting hospital characteristics.

    RESULTS—Despite being at significantly higher risk for death at baseline, diabetic patients were less likely to be followed-up by a cardiologist (22.2 vs. 25.6%, P < 0.001), to receive myocardial revascularization (12.6 vs. 14.9%, P < 0.001), to receive β-blockers (34.2 vs. 44.0%, P < 0.001), and to receive aspirin therapy (59.7 vs. 63.5%, P < 0.001) after AMI than their nondiabetic counterparts. Diabetes was an important independent predictor of 5-year morbidity (adjusted hazard ratio 1.52, 95% CI 1.45–1.59) and 5-year mortality outcomes (1.57, 1.50–1.63). Variations in processes of care were marginally associated with higher nonfatal complication rates for diabetic patients.

    CONCLUSIONS—When managing AMI patients with diabetes in Ontario, physician treatment aggressiveness does not correspond appropriately to the baseline risk of patients.


    • Address correspondence and reprint requests to Dr. David A. Alter, Institute for Clinical Evaluative Sciences G106-2075 Bayview Ave., Toronto, Ontario M4N 3M5. E-mail: david.alter{at}

      Received for publication 16 September 2002 and accepted in revised form 17 January 2003.

      The results, conclusions, and opinions are those of the authors, and no endorsement by the Ontario Ministry of Health, the Institute for Clinical Evaluative Sciences, or the CIHR is intended or should be inferred.

      A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

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