Development and Validation of a Multifactorial Risk Index for Predicting Postoperative Pneumonia after Major Noncardiac Surgery

  1. Ahsan M. Arozullah, MD, MPH;
  2. Shukri F. Khuri, MD;
  3. William G. Henderson, PhD;
  4. Jennifer Daley, MD; and
  5. for the Participants in the National Veterans Affairs Surgical Quality Improvement Program
  1. From Veterans Affairs Chicago Healthcare System, Westside Division, University of Illinois College of Medicine, Chicago, and Hines Veterans Affairs Cooperative Studies Program Coordinating Center, Hines, Illinois; Veterans Affairs Boston Healthcare System, West Roxbury, Massachusetts; and Harvard Medical School, Brigham and Women's Hospital, and Center for Health System Design and Evaluation/Institute for Health Policy, Massachusetts General Hospital/Partners Health Care System, Boston, Massachusetts.

    Abstract

    Background: Pneumonia is a common postoperative complication associated with substantial morbidity and mortality.

    Objective: To develop and validate a preoperative risk index for predicting postoperative pneumonia.

    Design: Prospective cohort study with outcome assessment based on chart review.

    Setting: 100 Veterans Affairs Medical Centers performing major surgery.

    Patients: The risk index was developed by using data on 160 805 patients undergoing major noncardiac surgery between 1 September 1997 and 31 August 1999 and was validated by using data on 155 266 patients undergoing surgery between 1 September 1995 and 31 August 1997. Patients with preoperative pneumonia, ventilator dependence, and pneumonia that developed after postoperative respiratory failure were excluded.

    Measurements: Postoperative pneumonia was defined by using the Centers for Disease Control and Prevention definition of nosocomial pneumonia.

    Results: A total of 2466 patients (1.5%) developed pneumonia, and the 30-day postoperative mortality rate was 21%. A postoperative pneumonia risk index was developed that included type of surgery (abdominal aortic aneurysm repair, thoracic, upper abdominal, neck, vascular, and neurosurgery), age, functional status, weight loss, chronic obstructive pulmonary disease, general anesthesia, impaired sensorium, cerebral vascular accident, blood urea nitrogen level, transfusion, emergency surgery, long-term steroid use, smoking, and alcohol use. Patients were divided into five risk classes by using risk index scores. Pneumonia rates were 0.2% among those with 0 to 15 risk points, 1.2% for those with 16 to 25 risk points, 4.0% for those with 26 to 40 risk points, 9.4% for those with 41 to 55 risk points, and 15.3% for those with more than 55 risk points. The C-statistic was 0.805 for the development cohort and 0.817 for the validation cohort.

    Conclusions: The postoperative pneumonia risk index identifies patients at risk for postoperative pneumonia and may be useful in guiding perioperative respiratory care.

    Article and Author Information

    • Acknowledgments: The authors thank Kwan Hur, PhD, for assistance with statistical analysis.

    • Grant Support: The Office of Patient Care Services and the Health Services Research and Development Service of the Department of Veterans Affairs (grant SDR 91) funded The National VA Surgical Quality Improvement Program. Dr. Arozullah is a Research Associate in the Career Development Award Program of the Veterans Affairs Health Services Research and Development Service. Dr. Daley was a Senior Research Associate in the Career Development Award Program of the Veterans Affairs Health Services Research and Development Service at the time that this research was conducted.

    • Requests for Single Reprints: Ahsan M. Arozullah, MD, MPH, Section of General Internal Medicine (M/C 787), University of Illinois College of Medicine, 840 South Wood Street, Room 440-M, Chicago, IL 60612-7323; e-mail, arozulla{at}uic.edu.

    • Current Author Addresses: Dr. Arozullah: Section of General Internal Medicine (M/C 787), University of Illinois College of Medicine, 840 South Wood Street, Room 440-M, Chicago, IL 60612-7323.

    • Dr. Khuri: Surgical Service (112), Veterans Affairs Boston Healthcare System, 1400 VFW Parkway, West Roxbury, MA 02132.

    • Dr. Henderson: Cooperative Studies Program Coordinating Center (151K), Hines Veterans Affairs Hospital, Fifth Avenue and Roosevelt Road, Hines, IL 60141.

    • Dr. Daley: Institute for Health Policy, Massachusetts General Hospital/Partners HealthCare System, 50 Staniford Street, Ninth Floor, Boston, MA 02114.

    • Author Contributions: Conception and design: A.M. Arozullah, J. Daley.

    • Analysis and interpretation of the data: A.M. Arozullah.

    • Drafting of the article: A.M. Arozullah, S.F. Khuri, W.G. Henderson, J. Daley.

    • Critical revision of the article for important intellectual content: A.M. Arozullah, S.F. Khuri, W.G. Henderson, J. Daley.

    • Final approval of the article: A.M. Arozullah, S.F. Khuri, W.G. Henderson, J. Daley.

    • Provision of study materials or patients: S.F. Khuri, W.G. Henderson, J. Daley.

    • Statistical expertise: A.M. Arozullah, W.G. Henderson.

    • Obtaining of funding: S.F. Khuri, W.G. Henderson, J. Daley.

    • Administrative, technical, or logistic support: S.F. Khuri, W.G. Henderson, J. Daley.

    • Collection and assembly of data: S.F. Khuri, W.G. Henderson, J. Daley.

    Summary for Patients

    « Previous | Next Article »Table of Contents

    This Article

    1. Ann Intern Med November 20, 2001 vol. 135 no. 10 847-857
    1. » Abstract
    2. Full Text
    3. Full Text (PDF)
      1. Summary for Patients

    Rapid Responses

    1. Submit a response
    2. No responses published

    Current Issue

    1. November 17, 2009, 151 (10)
    1. Alert me to current issues