Association of physician and hospital volume with use of aspirin and reperfusion therapy in acute myocardial infarction.
BACKGROUND
The association between volume of patients treated and quality of care has important implications for patient referral policies and approaches to quality improvement. Most studies have focused on hospital volume alone and health outcomes.


OBJECTIVE
The objective of this work was to examine the association of hospital and physician volume with use of aspirin and reperfusion therapy in the management of acute myocardial infarction (AMI) in eligible patients.


METHODS
We reviewed charts of 2,215 patients treated at 35 Minnesota hospitals for AMI between October 1, 1992, and July 31, 1993, comparing use of aspirin and reperfusion therapy in eligible patients across different physician and hospital volume categories through multiple logistic regression.


RESULTS
Aspirin use did not vary significantly with physician volume. Use of reperfusion therapy was reduced among the lowest-volume physicians only (adjusted OR, 0.38; 95% CI, 0.15-0.94). Compared with the highest volume hospitals (treating >200 patients), aspirin use among lower-volume hospitals was lower. This was statistically significant only in the hospitals treating <30 patients (adjusted OR, 0.54; 95% CI, 0.30-0.97). These same hospitals had increased odds of using thrombolytics (adjusted OR, 3.02; 95% CI, 1.40-6.53).


CONCLUSIONS
Differences in use of aspirin and reperfusion therapy occur at the extremes of hospital and physician volume. These observed differences are in the anticipated direction, except for the increased use of thrombolytics at very-low-volume hospitals. This may be a "desperation reaction" with a perceived lack of other alternatives, such as cardiac catheterization labs and cardiologists.
Willison
D J
DJ
Centre for Evaluation of Medicines, St. Joseph's Hospital, and Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, Ontario, Canada. willison@mcmaster.ca
Soumerai
S B
SB
Palmer
R H
RH
D000328:Adult; D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D017723:Drug Utilization Review / Q000706:statistics & numerical data*; D005260:Female; D005343:Fibrinolytic Agents / Q000627:therapeutic use*; D006302:Health Services Research; D006761:Hospitals / Q000592:standards* / Q000706:statistics & numerical data*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008485:Medical Audit; D008505:Medical Staff, Hospital / Q000592:standards* / Q000706:statistics & numerical data*; D008875:Middle Aged; D008910:Minnesota; D009203:Myocardial Infarction / Q000188:drug therapy*; D010043:Outcome and Process Assessment, Health Care; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013997:Time Factors; D017749:Total Quality Management; D016526:Workload
D005343:Fibrinolytic Agents; D001241:Aspirin