Table 3

Definitions of outcomes and postoperative events

Myocardial infarction37An elevation in serum troponin that both
  • Exceeds the 99th centile of the normal reference population

  • Exceeds the threshold at which the coefficient of variation for the assay is 10%

  • At least one of the following must be present:

  • Clinical symptoms of ischaemia

  • Typical ECG changes of ischaemia

  • New pathological Q-waves on ECG

  • Coronary artery intervention

  • New (or presumed new) changes on echocardiography or radionuclide imaging

Myocardial injury1An elevation in serum troponin that both
  • Exceeds the 99th centile of the normal reference population

  • Exceeds the threshold at which the coefficient of variation for the assay is 10%

Non-fatal cardiac arrest1Successful resuscitation from documented (or presumed) ventricular fibrillation, sustained ventricular tachycardia, asystole, or pulseless electrical activity
Heart failure1Presence of both
  • Clinical findings (ie, elevated jugular venous pressure, respiratory rales, crepitations, S3 heart sounds)

  • Radiological findings (ie, vascular redistribution, interstitial or frank pulmonary oedema)

Stroke1New focal neurological deficit, suspected to vascular in origin, with signs/symptoms lasting ≥24 h
Transient ischaemic attackTransient focal neurological deficit that lasts less than 24 h and is thought to be vascular in origin
Respiratory failure60Need for tracheal intubation and mechanical ventilation after patient has completed surgery, been successful extubated, and breathing spontaneously for >1 h
Pneumonia1Documented hypoxaemia (PaO2/FiO2 ratio ≤250 mm Hg) or fever (temperature >37.5°C) with either:
  1. Rales or dullness to percussion on chest examination and any of (i) new onset of purulent sputum or change in sputum character; (ii) organism isolated from blood culture; or (iii) pathogen isolated from transtracheal aspirate, bronchial brushing or biopsy

  2. New or progressive infiltrate, consolidation, cavitation or pleural effusion on chest radiograph and any of (1) criteria i, ii or iii above; (2) detection of virus or viral antigen in respiratory secretions; (3) diagnostic antibody titres; or (4) histopathological evidence of pneumonia

Surgical site infectionPhysician diagnosis of surgical site infection during:
  • Index hospitalisation

  • Outpatient visit, hospital readmission or emergency room visit within 30 days after index surgery

Deep venous thrombosis1Any of the following during index hospitalisation:
  1. Persistent intraluminal filling defect on contrast venography

  2. One or more non-compressible venous segments on B mode compression ultrasonography

  3. Clearly defined intraluminal filling defect on contrast-enhanced CT

Pulmonary embolism1Any of the following during index hospitalisation:
  1. High probability ventilation/perfusion lung scan

  2. Intraluminal filling defect of segmental or larger artery on a helical CT scan

  3. Intraluminal filling defect on pulmonary angiography

  4. A positive diagnostic test for DVT (eg, positive compression ultrasound) plus low or intermediate probability ventilation/perfusion lung scan, or non-diagnostic (subsegmental defects or technically inadequate study) helical CT scan

Significant bleedingBlood loss with any of the following characteristics:
  1. Results in drop in haemoglobin of 30 g/L or more

  2. Leads to red cell transfusion or re-operation

  3. Is considered to the cause of death

Postoperative complications*Severity of complications are classified (based on most severe events during the index hospitalisation) as:
  1. None

  2. Mild: only temporary harm that does not require clinical treatment

  3. Moderate: required clinical treatment but without significantly prolonged hospital stay. Does not usually result in permanent harm and where this does occur, the harm does not cause functional limitation

  4. Severe—requires clinical treatment and results in significant prolongation of hospital stay and/or permanent functional limitation

  5. Fatal—death from the complication

General health utilities36Measured at study recruitment, 30 days after surgery and 1 year after surgery using the EuroQol EQ-5D
  • *Severity of complications are classified based on scheme adapted from Clavien-Dindo classification system.61

  • DVT, deep vein thrombosis; FiO2, fractional inspired oxygen; PaO2, arterial oxygen tension.