PMID- 20117015
OWN - NLM
STAT- MEDLINE
DCOM- 20110223
LR  - 20100503
IS  - 1873-734X (Electronic)
IS  - 1010-7940 (Linking)
VI  - 37
IP  - 5
DP  - 2010 May
TI  - A preoperative risk prediction model for 30-day mortality following cardiac 
      surgery in an Australian cohort.
PG  - 1086-92
LID - 10.1016/j.ejcts.2009.11.021 [doi]
AB  - BACKGROUND: Population-specific risk models are required to build consumer and 
      provider confidence in clinical service delivery, particularly when the risks may 
      be life-threatening. Cardiac surgery carries such risks. Currently, there is no 
      model developed on the Australian cardiac surgery population and this article 
      presents a novel risk prediction model for the Australian cohort with the aim to 
      provide a guide for the surgeons and patients in assessing preoperative risk 
      factors for cardiac surgery. AIMS: This study aims to identify preoperative risk 
      factors associated with 30-day mortality following cardiac surgery for an 
      Australian population and to develop a preoperative model for risk prediction. 
      METHODS: All patients (23016) undergoing cardiac surgery between July 2001 and 
      June 2008 recorded in the Australian Society of Cardiac and Thoracic Surgeons 
      (ASCTS) database were included in this analysis. The data were divided randomly 
      into model creation (13810, 60%) and model validation (9206, 40%) sets. The model 
      was developed on the creation set and then validated on the validation set. The 
      bootstrap sampling and automated variable selection methods were used to develop 
      several candidate models. The final model was selected from this group of 
      candidate models by using prediction mean square error (MSE) and Bayesian 
      Information Criteria (BIC). Using a multifold validation, the average receiver 
      operating characteristic (ROC), p-value for Hosmer-Lemeshow chi-squared test and 
      MSE were obtained. Risk thresholds for low-, moderate- and high-risk patients 
      were defined. The expected and observed mortality for various risk groups were 
      compared. The multicollinearity and first-order interaction effect between 
      clinically meaningful risk factors were investigated. RESULTS: A total of 23016 
      patients underwent cardiac surgery and the 30-day mortality rate was 3.2% (728 
      patients). Independent predictors of mortality in the model were: age, sex, the 
      New York Heart Association (NYHA) class, urgency of procedure, ejection fraction 
      estimate, lipid-lowering treatment, preoperative dialysis, previous cardiac 
      surgery, procedure type, inotropic medication, peripheral vascular disease and 
      body mass index (BMI). The model had an average ROC 0.8223 (95% confidence 
      interval (CI): 0.8118-0.8227), p-value 0.8883 (95% CI: 0.8765-0.90) and MSE 
      0.0251 (95% CI: 0.02515-0.02516). The validation set had observed mortality 3.0% 
      (95% CI: 2.7-3.3%) and predicted mortality 2.9% (95% CI: 2.6-3.2%). The low-risk 
      group (additive score 0-3) had 0.6% observed mortality (95% CI: 0.3-0.9%) and 
      0.5% predicted mortality (95% CI: 0.2-0.8%). The moderate-risk group (additive 
      score 4-9) had 1.7% observed mortality (95% CI: 1.2-2.2%) and 1.4% predicted 
      mortality (95% CI: 1.0-1.8%). The observed mortality for the high-risk group 
      (additive score 9 plus) was 6.7% (95% CI: 5.8-7.6%) and the expected mortality 
      was 6.7% (95% CI: 5.8-7.6%). CONCLUSION: A preoperative risk prediction model for 
      30-day mortality was developed for the Australian cardiac surgery population.
CI  - Copyright 2010 European Association for Cardio-Thoracic Surgery. Published by 
      Elsevier B.V. All rights reserved.
FAU - Billah, Baki
AU  - Billah B
AD  - Department of Epidemiology & Preventive Medicine, Monash University, 89 
      Commercial Road, Melbourne, VIC 3004, Australia. baki.billah@med.monash.edu.au
FAU - Reid, Christopher Michael
AU  - Reid CM
FAU - Shardey, Gilbert C
AU  - Shardey GC
FAU - Smith, Julian A
AU  - Smith JA
LA  - eng
PT  - Journal Article
DEP - 20100208
PL  - Germany
TA  - Eur J Cardiothorac Surg
JT  - European journal of cardio-thoracic surgery : official journal of the European 
      Association for Cardio-thoracic Surgery
JID - 8804069
SB  - IM
MH  - Age Factors
MH  - Aged
MH  - Aged, 80 and over
MH  - Australia/epidemiology
MH  - Cardiac Surgical Procedures/adverse effects/methods/*mortality
MH  - Emergencies
MH  - Epidemiologic Methods
MH  - Female
MH  - *Health Status Indicators
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - Preoperative Care/methods
MH  - Prognosis
MH  - Sex Factors
EDAT- 2010/02/02 06:00
MHDA- 2011/02/24 06:00
CRDT- 2010/02/02 06:00
PHST- 2009/06/22 00:00 [received]
PHST- 2009/11/03 00:00 [revised]
PHST- 2009/11/09 00:00 [accepted]
PHST- 2010/02/02 06:00 [entrez]
PHST- 2010/02/02 06:00 [pubmed]
PHST- 2011/02/24 06:00 [medline]
AID - S1010-7940(09)01061-6 [pii]
AID - 10.1016/j.ejcts.2009.11.021 [doi]
PST - ppublish
SO  - Eur J Cardiothorac Surg. 2010 May;37(5):1086-92. doi: 
      10.1016/j.ejcts.2009.11.021. Epub 2010 Feb 8.