Context Acute myocardial infarction (AMI) is a common condition that is treated
by physicians with varying levels of clinical experience, but whether the
level of experience affects outcome remains uncertain.
Objective To evaluate the relationship between the average annual volume of cases
treated by admitting physicians and mortality after AMI.
Design, Setting, and Patients Retrospective cohort study using linked administrative databases containing
patient admission information for 98 194 patients treated by 5374 physicians
between April 1, 1992, and March 31, 1998, in Ontario, Canada.
Main Outcome Measures Mortality risk rates for 30 days and 1 year post-AMI, adjusted by physician
volume and patient, physician, and hospital characteristics.
Results The 30-day mortality rate was 13.5% and the 1-year mortality rate was
21.8%. A strong inverse relationship between the average annual volume of
AMI cases treated by the admitting physician and mortality after an AMI was
observed. The 30-day risk-adjusted mortality rate was 15.3% for physicians
who treated 5 or fewer AMI cases per year (lowest quartile) compared with
11.8% for physicians who treated more than 24 AMI cases annually (highest
quartile; P<.001). The 1-year risk-adjusted mortality
rate was 24.2% for physicians who treated 5 or fewer AMI cases per year (lowest
quartile) compared with 19.6% for physicians who treated more than 24 AMI
cases annually (highest quartile; P<.001).
Conclusion Patients with AMI who are treated by high-volume admitting physicians
are more likely to survive at 30 days and 1 year.