title: Defining operative mortality: Impact on outcome reporting.
abstract: OBJECTIVE
  Death is an important outcome of procedural interventions. The death rate, or mortality rate, is subject to variability by definition. The Society of Thoracic Surgeons Adult Cardiac Surgery Database definition of "operative" mortality originally included all in-hospital deaths and deaths occurring within 30 days of the procedure. In recent versions of the Society of Thoracic Surgeons Adult Cardiac Surgery Database, "in-hospital" has been modified to include "patients transferred to other acute care facilities," and "deaths within 30 days unless clearly unrelated to the procedure" has been changed to "deaths within 30 days regardless of cause." This study addresses the impact of these redefinitions on outcome reporting.
  
  
  METHODS
  The California Office of Statewide Health Planning and Development hospitalized patient discharge database was queried for the year 2009, the most recent year that data files could be linked to the vital statistics death files to include all-cause mortality. Isolated coronary artery bypass grafting, isolated valve, coronary artery bypass grafting valve, and percutaneous coronary intervention procedures were identified by International Classification of Diseases, Ninth Edition, Clinical Modification procedure codes. Percutaneous coronary intervention procedures were further divided into acute coronary syndrome (percutaneous coronary intervention acute coronary syndrome) and all other percutaneous coronary intervention (percutaneous coronary intervention no acute coronary syndrome). Deaths were counted by 5 methods depending on the time and place of occurrence: (1) in-hospital or during the index hospitalization; (2) in-hospital + connected hospitalization, defined as a transfer to another acute care facility on the same day or within 24 hours of discharge; (3) in-hospital + 30 day, death during index hospitalization or within 30 days after the procedure; (4) in-hospital + connected + 30 day readmission, death during index hospitalization, transfer to acute care facility, or deaths during readmission within 30 days; and (5) in-hospital + connected + 30 day. To study the impact of these operative mortality definitions, we examined 5 different methods to track mortality and performed 2 separate analyses. The first analysis did not exclude any patients, and the second analysis excluded any patient who could not be accurately tracked after hospital discharge.
  
  
  RESULTS
  In the first analysis with no patients excluded, a total of 17% (117/697) of surgical deaths and 31% (409/1324) of percutaneous coronary intervention deaths were counted after the original hospitalization. The highest percentage of posthospital deaths occurred after elective percutaneous coronary intervention: 45% (135/301). In surgical patients, the highest percentage of posthospital deaths occurred in coronary artery bypass grafting procedures: 20% (57/284). In the second analysis, with untrackable patients excluded, hospital deaths included 12% (161/1324) for percutaneous coronary intervention compared with 4% (30/697) for surgical procedures.
  
  
  CONCLUSIONS
  A significant percentage of procedural deaths occur after transfer or discharge from the index hospital. This is especially evident in the percutaneous coronary intervention group. These findings illustrate the importance of the definition of "operative" mortality and the need to ensure accuracy in the reporting of data to voluntary clinical registries, such as the Society of Thoracic Surgeons Adult Cardiac Surgery Database and National Cardiovascular Data Registry.
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, University of California Irvine Medical Center, Orange, Calif. Electronic address: smaximus@uci.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Maximus
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, University of California Irvine Medical Center, Orange, Calif.
authors.forename: Jeffrey C
authors.initials: JC
authors.lastname: Milliken
authors.affiliation: Health Information Solutions, Rocklin, Calif.
authors.forename: Beate
authors.initials: B
authors.lastname: Danielsen
authors.affiliation: Department of Cardiothoracic Surgery, East Bay Cardiac Surgery Center, Oakland, Calif.
authors.forename: Junaid
authors.initials: J
authors.lastname: Khan
authors.affiliation: University of California Los Angeles Ronald Reagan Medical Center, Los Angeles, Calif.
authors.forename: Richard
authors.initials: R
authors.lastname: Shemin
authors.affiliation: Division of Cardiothoracic Surgery, Department of Surgery, University of California Irvine Medical Center, Orange, Calif.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Carey
mesh_terms: D002140:California / Q000453:epidemiology; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality* / Q000639:trends; D001026:Coronary Artery Bypass / Q000401:mortality; D016208:Databases, Factual / Q000706:statistics & numerical data; D017558:Elective Surgical Procedures / Q000401:mortality; D006331:Heart Diseases / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000401:mortality* / Q000639:trends; D019984:Quality Indicators, Health Care; D012107:Research Design / Q000706:statistics & numerical data*; D012307:Risk Factors; D009626:Terminology as Topic; D013997:Time Factors; D016896:Treatment Outcome
keywords: CABG; PCI; cardiac surgery; operative mortality; outcome reporting