1. Cardiac surgery report cards: making the grade
Gary L Grunkemeier, PhD, Kathryn J Zerr, RN, MBA, Ruyun Jin, MD 
The Annals of Thoracic Surgery 
Volume 72, Issue 6, Pages (December 2001)
DOI: /S (01)

2. Fig 2
Observed over expected (O/E) mortality for coronary artery bypass grafting patients from 9 Providence Health System hospitals. Area of the symbols is proportional to the number of patients. The horizontal location of each symbol indicates the O/E ratio using conventional analysis, with 95% (solid horizontal lines) and 99.4% (dashed horizontal lines) confidence intervals. The vertical location of each symbol indicates the O/E ratio based on a heirarchical model, as recommended by Shahian and associates [1]. Note that the hierarchical hospital estimates are all closer to unity (“shrunk” towards the mean) than the conventional estimates.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

3. Fig 1
Comparison of observed to expected mortality for individual patients, based on a risk model using Providence Health System data. For a continuous variable, one can expect the data points to be clustered around the line of identity, but for a binary outcome variable, this is not possible. The points fall far from this line, yet this risk model from which the expected mortality was derived has a C-index of 0.80.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )