Jacquelyn A Quin1,2, Brack Hattler3,4, Annie Laurie W Shroyer5,6, Darlene Kemp7, G Hossein Almassi8,9, Faisal G Bakaeen10,11, Brendan M Carr12,13, Muath Bishawi12,14, Joseph F Collins7, Frederick L Grover4,15, Todd H Wagner16,17. 1. Surgical Service, Veterans Affairs Boston Healthcare System, West Roxbury, Massachusetts. 2. Harvard Medical School, Boston, Massachusetts. 3. Department of Medicine, Division of Cardiology, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado. 4. School of Medicine at the Anschutz Medical Campus, University of Colorado, Aurora, Colorado. 5. Research and Development Office, Northport Veterans Affair Medical Center, Northport, New York. 6. Research and Development Office, Eastern Colorado Health Care System, Department of Veterans Affairs, Denver, Colorado. 7. Cooperative Studies Program Coordinating Center, Veterans Affairs Medical Center, Perry Point, Maryland. 8. Surgical Services, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin. 9. Department of Surgery, Division of Cardiothoracic Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin. 10. Pittsburgh VA Medical Center, Pittsburgh, Pennsylvania. 11. Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, Cleveland, Ohio. 12. Research and Development Office, Northport Veterans Affairs Medical Center, Northport, New York. 13. Department of Emergency Medicine, Mayo Clinic, Rochester, Minnesota. 14. Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Durham, North Carolina. 15. Department of Surgery, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado. 16. Veterans Affairs Palo Alto Health Economics Resource Center, Menlo Park, California. 17. Department of Surgery, Stanford University, Stanford, California.
Abstract
BACKGROUND: The optimal methodology to identify cardiac versus non-cardiac cause of death following cardiac surgery has not been determined. METHODS: The Randomized On/Off Bypass Trial was a multicenter, randomized, controlled clinical trial of 2203 patients (February 2002-May 2008) comparing 1-year cardiac outcomes between off-pump and on-pump bypass surgery. In 2013, the Veterans Affairs (VA) Cooperative Studies Program funded a follow-up study to assess 5-year outcomes including mortality. Deaths were identified and confirmed using the National Death Index (NDI), VA Vital Status file, and medical records. An Endpoints Committee (EC) reviewed patient medical records and classified each cause of death as cardiac, non-cardiac, or unknown. Using pre-determined ICD-10 codes, NDI death certificates were independently used to classify deaths as cardiac or non-cardiac. Cause of death was compared between the NDI and EC classifications and concordance measured, using Kappa statistics. RESULTS: Of the 297 5-year deaths identified by the NDI and/or VA vital status file and confirmed by the EC, 219 had adequate patient records for EC cause of death determination. The EC adjudicated 141 of these deaths as non-cardiac and 78 as cardiac, while the NDI classified 150 as non-cardiac and 69 as cardiac; agreement was 77.6% (kappa 0.500; P < 0.001). CONCLUSIONS: Since concordance between EC and NDI cause of death classifications was only moderate, caution should be exercised in relying exclusively on NDI data to determine cause of death. A hybrid approach, integrating multiple information sources, may provide the most accurate approach to classifying cause of death.
RCT Entities:
BACKGROUND: The optimal methodology to identify cardiac versus non-cardiac cause of death following cardiac surgery has not been determined. METHODS: The Randomized On/Off Bypass Trial was a multicenter, randomized, controlled clinical trial of 2203 patients (February 2002-May 2008) comparing 1-year cardiac outcomes between off-pump and on-pump bypass surgery. In 2013, the Veterans Affairs (VA) Cooperative Studies Program funded a follow-up study to assess 5-year outcomes including mortality. Deaths were identified and confirmed using the National Death Index (NDI), VA Vital Status file, and medical records. An Endpoints Committee (EC) reviewed patient medical records and classified each cause of death as cardiac, non-cardiac, or unknown. Using pre-determined ICD-10 codes, NDI death certificates were independently used to classify deaths as cardiac or non-cardiac. Cause of death was compared between the NDI and EC classifications and concordance measured, using Kappa statistics. RESULTS: Of the 297 5-year deaths identified by the NDI and/or VA vital status file and confirmed by the EC, 219 had adequate patient records for EC cause of death determination. The EC adjudicated 141 of these deaths as non-cardiac and 78 as cardiac, while the NDI classified 150 as non-cardiac and 69 as cardiac; agreement was 77.6% (kappa 0.500; P < 0.001). CONCLUSIONS: Since concordance between EC and NDI cause of death classifications was only moderate, caution should be exercised in relying exclusively on NDI data to determine cause of death. A hybrid approach, integrating multiple information sources, may provide the most accurate approach to classifying cause of death.