Figure 4
From: Case-mix and the use of control charts in monitoring mortality rates after coronary artery bypass
Longitudinal P-charts of risk-adjusted mortality after coronary artery bypass grafting in New York hospitals 1994–2003 for 27 hospitals (each panel). Horizontal line is the mean mortality with exact upper and lower control limits shown as stepped lines (solid stepped lines are 99.9% probability limits and dotted stepped lines are 95% probability limits).