Sex Differences in Cardiac Catheterization after Acute Myocardial Infarction: The Role of Procedure Appropriateness

17 September 2002 | Volume 137 Issue 6 | Pages 487-493

Background: Many studies have found that women are less likely than men to have cardiac catheterization after an acute myocardial infarction; however, it is unknown whether sex differences reflect inappropriate treatment.

Objective: To ascertain whether cardiac catheterization use after acute myocardial infarction in men and women varied by sex and the appropriateness of the procedure, as determined by clinical guidelines.

Design: Retrospective analysis of chart-abstracted data.

Setting: U.S. acute-care hospitals.

Patients: 143 444 Medicare patients who were hospitalized for acute myocardial infarction between 1994 and 1996.

Measurements: Cardiac catheterization use within 60 days of hospitalization for acute myocardial infarction.

Results: Women had lower crude rates of cardiac catheterization than men (35.7% for women vs. 46.5% for men [P < 0.001]; difference, 10.8 percentage points). Multivariable adjustment for demographic, clinical, and hospital characteristics reduced most of the sex differences in procedure use (risk-standardized rates, 40.3% for women vs. 41.9% for men [P < 0.001]; difference, 1.6 percentage points). Sex differences in cardiac catheterization use varied by the appropriateness of the procedure. Risk-standardized rates of cardiac catheterization were similar for men and women with strong indications for the procedure (44.1% for women vs. 44.6% for men [P > 0.2]; difference, 0.5 percentage point). Rates of cardiac catheterization use among patients with weak indications did not significantly differ between men and women (16.5% for women vs. 18.0% for men [P = 0.096]; difference, 1.5 percentage points). Sex differences in cardiac catheterization use were largest for patients with equivocal indications (39.4% for women vs. 42.5% for men [P < 0.001]; difference, 3.1 percentage points).

Conclusions: Among elderly persons, women have lower rates of cardiac catheterization use after an acute myocardial infarction than men. However, this difference was attenuated after multivariable adjustment, and it occurred primarily in patients with equivocal indications. We found no sex variations in procedure use among patients who had strong indications for cardiac catheterization.

Editors' Notes Context Women have cardiac catheterization after an acute myocardial infarction less often than men; however, the reason—gender bias or clinical factors—is unknown. Contribution This large retrospective study of elderly Medicare patients compared numbers of indicated (guideline-recommended) and actual catheterizations performed within 60 days of acute myocardial infarction for women and men. Overall, women less often had cardiac catheterization than men but rates of the procedure did not differ between women and men with clear-cut guideline indications for catheterization. Implications Differences in catheterization use after acute myocardial infarction usually reflect appropriate clinical decisions rather than gender bias. –The Editors

 

Author and Article Information

From Yale University School of Medicine, New Haven, Connecticut; Yale–New Haven Hospital, New Haven, Connecticut; Qualidigm, Middletown, Connecticut; and Centers for Medicare & Medicaid Services, Boston, Massachusetts.

Disclaimer: The content of this publication does not necessarily reflect the views or policies of the U.S. Department of Health and Human Services, nor does mention of trade names, commercial products, or organization imply endorsement by the U.S. government. The author assumes full responsibility for the accuracy and completeness of the ideas presented. This article is a direct result of the Health Care Quality Improvement Program initiated by the Centers for Medicare & Medicaid Services (formerly Health Care Financing Administration), which has encouraged identification of quality improvement projects derived from analysis of patterns of care and, therefore, required no special funding on the part of this contractor.

Acknowledgments: The authors thank Maria Johnson, BA, for editorial assistance and Jeph Herrin, PhD, for statistical assistance.

Grant Support: By the Centers for Medicare & Medicaid Services (CMS, formerly the Health Care Financing Administration), U.S. Department of Health and Human Services (contract number 500-99-CTO1: "Utilization and Quality Control Peer Review Organization for the State of Connecticut").

Corresponding Author: Harlan Krumholz, MD, Department of Internal Medicine, Room IE-61 SHM, Yale University School of Medicine, 333 Cedar Street, PO Box 208025, New Haven, CT 06520-8025; email, harlan.krumholz{at}yale.edu.

Current Author Addresses: Mr. Rathore, Mr. Wang, and Drs. Radford and Krumholz: Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, 333 Cedar Street, Room I-456 SHM, PO Box 208025, New Haven, CT 06520-8025.

Dr. Ordin: Centers for Medicare & Medicaid Services Boston Regional Office, Government Center, JFK Federal Building, Room 2350, Boston, MA 02203.

Author Contributions: Conception and design: S.S. Rathore, H.M. Krumholz.

Analysis and interpretation of the data: S.S. Rathore, Y. Wang, H.M. Krumholz.

Drafting of the article: S.S. Rathore.

Critical revision of the article for important intellectual content: S.S. Rathore, Y. Wang, M.J. Radford, D.L. Ordin, H.M. Krumholz.

Final approval of the article: S.S. Rathore, Y. Wang, M.J. Radford, D.L. Ordin, H.M. Krumholz.

Provision of study materials or patients: H.M. Krumholz.

Statistical expertise: S.S. Rathore, Y. Wang, H.M. Krumholz.

Obtaining of funding: M.J. Radford, H.M. Krumholz.

Administrative, technical, or logistic support: M.J. Radford, D.L. Ordin, H.M. Krumholz.