Send to

Choose Destination
Lancet. 1995 Oct 21;346(8982):1085-7.

Comparing methods of measurement: why plotting difference against standard method is misleading.

Author information

Department of Public Health Sciences, St George's Hospital Medical School, London, UK.


When comparing a new method of measurement with a standard method, one of the things we want to know is whether the difference between the measurements by the two methods is related to the magnitude of the measurement. A plot of the difference against the standard measurement is sometimes suggested, but this will always appear to show a relation between difference and magnitude when there is none. A plot of the difference against the average of the standard and new measurements is unlikely to mislead in this way. We show this theoretically and by a practical example.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center