title: Predictors of total morbidity burden on days 3, 5 and 8 after cardiac surgery.
abstract: BACKGROUND
  Post-operative morbidity affects up to 36% of cardiac surgical patients. However, few countries reliably record morbidity outcome data, despite patients wanting to be informed of all the risks associated with surgery. The Cardiac Post-Operative Morbidity Score (C-POMS) is a new tool for describing and scoring (0-13) total morbidity burden after cardiac surgery, derived by noting the presence/absence of 13 morbidity domains on days 3, 5, 8 and 15. Identifying modifiable C-POMS risk factors may suggest targets for intervention to reduce morbidity and healthcare costs. Thus, we explored the association of C-POMS with previously identified predictors of post-operative morbidity.
  
  
  METHODS
  A systematic literature review of pre-operative risk assessment models for post-operative morbidity was conducted to identify variables associated with post-operative morbidity. The association of those variables with C-POMS was explored in patients drawn from the original C-POMS study (n= 444).
  
  
  RESULTS
  Seventy risk factors were identified, of which 56 were available in the study and 49 were suitable for analysis. Numbers were too few to analyse associations on D15. Thirty-three (67.3%) and 20 (40.8%) variables were associated with C-POMS on at least 1 or 2 days, respectively. Pre-operative albumin concentration, left ventricular ejection fraction and New York Heart Association functional class were associated with C-POMS on all days. Of the 16 independent risk factors, pre-operative albumin and haemoglobin concentrations and weight are potentially modifiable.
  
  
  CONCLUSIONS
  Different risk factors are associated with total morbidity burden on different post-operative days. Pre-operative albumin and haemoglobin concentrations and weight were independently predictive of post-operative total morbidity burden suggesting therapeutic interventions aimed at these might reduce both post-operative morbidity risk and health-care costs in patients undergoing cardiac surgery.
authors.affiliation: St Bartholomew's Hospital, Barts Health NHS Trust, London, UK.|Institute for Sport, Exercise and Health, University College London, 1st Floor 170 Tottenham Court Rd, London, W1T 7HA UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Sanders
authors.affiliation: Centre for Cardiovascular Genetics, University College London, London, UK.
authors.forename: Jackie
authors.initials: J
authors.lastname: Cooper
authors.affiliation: Institute for Sport, Exercise and Health, University College London, 1st Floor 170 Tottenham Court Rd, London, W1T 7HA UK.|Department of Anaesthesia, University College London Hospitals NHS Trust, London, UK.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Mythen
authors.affiliation: Institute for Sport, Exercise and Health, University College London, 1st Floor 170 Tottenham Court Rd, London, W1T 7HA UK.
authors.forename: Hugh E
authors.initials: HE
authors.lastname: Montgomery
keywords: C-POMS; Cardiac surgery; Morbidity outcome; Risk factor