TY - JOUR T1 - Funnel plots for institutional comparison JF - Quality and Safety in Health Care JO - Qual Saf Health Care SP - 390 LP - 391 DO - 10.1136/qhc.11.4.390-a VL - 11 IS - 4 AU - D Spiegelhalter Y1 - 2002/12/01 UR - http://qualitysafety.bmj.com/content/11/4/390.2.abstract N2 - Mohammed and colleagues1,2 have suggested the use of Shewhart control charts as a means of presenting performance indicator results without spurious ranking into “league tables”. They choose to plot the observed number of events against the volume of cases on a square root scale; unfortunately this choice appears unintuitive, obscures the observed event rates, and leads to rather approximate control limits. A … ER -