Funnel plots for comparing institutional performance

Stat Med. 2005 Apr 30;24(8):1185-202. doi: 10.1002/sim.1970.


'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'.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Biometry*
  • Cardiac Surgical Procedures / mortality
  • Coronary Artery Bypass / mortality
  • Coronary Artery Bypass / statistics & numerical data
  • Cross-Sectional Studies
  • England / epidemiology
  • Female
  • Humans
  • Infant
  • Odds Ratio
  • Outcome Assessment, Health Care
  • Pregnancy
  • Pregnancy in Adolescence / prevention & control
  • Pregnancy in Adolescence / statistics & numerical data
  • Quality Assurance, Health Care
  • Risk Factors