Premium
Funnel plots for comparing institutional performance
Author(s) -
Spiegelhalter David J.
Publication year - 2004
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/sim.1970
Subject(s) - funnel plot , spurious relationship , funnel , ranking (information retrieval) , statistics , econometrics , computer science , outcome (game theory) , analogy , mathematics , confidence interval , publication bias , environmental science , artificial intelligence , mathematical economics , environmental engineering , linguistics , philosophy
‘Funnel plots’ are recommended as a graphical aid for institutional comparisons, in which an estimate of an underlying quantity is plotted against an interpretable measure of its precision. ‘Control limits’ form a funnel around the target outcome, in a close analogy to standard Shewhart control charts. Examples are given for comparing proportions and changes in rates, assessing association between outcome and volume of cases, and dealing with over‐dispersion due to unmeasured risk factors. We conclude that funnel plots are flexible, attractively simple, and avoid spurious ranking of institutions into ‘league tables’. Copyright © 2004 John Wiley & Sons, Ltd.