1. Using Society of Thoracic Surgeons Risk Models for Risk-Adjusting Cardiac Surgery Results 
Ruyun Jin, MD, Anthony P. Furnary, MD, Stephanie C. Fine, MA, Eugene H. Blackstone, MD, Gary L. Grunkemeier, PhD 
The Annals of Thoracic Surgery 
Volume 89, Issue 3, Pages (March 2010)
DOI: /j.athoracsur
Copyright © 2010 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Diagram shows Society of Thoracic Surgeons (STS) models and the calibration process.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2010 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Cumulative Sum (CUSUM) graphs of Providence Health & Services Cardiovascular Disease Study Group in-hospital mortality, with and without calibration. The thick black CUSUM lines are based on calibrated risk scores and the thick grey CUSUM lines are based on uncalibrated risk scores. The smooth bullet-shaped curves are the 95% predication limits, with the same color code (black and grey, respectively). These prediction limits are slightly different because their computation is based on the risk scores. The vertical dashed lines indicate 250 cases.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2010 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Comparison of the uncalibrated risks of short length of stay (SLOS) and in-hospital mortality with the corresponding risks as calibrated by two different methods. The two lines below the diagonal line are predicted risk of in-hospital mortality; the two lines above the diagonal are predicted risk of short length of stay. The black lines show the calibrated risk by the observed/expected (O/E) method; the grey lines show the calibrated risk by the odds ratio (OR) method. Both methods force the observed death equal to the predicted death. Each short vertical bar represents a single patient. Most of the predicted risks for mortality are less than 15%. The predicted risks of SLOS are more widespread. Note that the calibrated risks of SLOS by the O/E method are greater than 100% in 4 patients, which is impossible for a true probability. This impossibility cannot occur with the OR method.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2010 The Society of Thoracic Surgeons Terms and Conditions