Applying the right statistics: analyses of measurement studies
Article first published online: 9 MAY 2003
Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Ultrasound in Obstetrics & Gynecology
Volume 22, Issue 1, pages 85–93, July 2003
How to Cite
Bland, J. M. and Altman, D. G. (2003), Applying the right statistics: analyses of measurement studies. Ultrasound Obstet Gynecol, 22: 85–93. doi: 10.1002/uog.122
- Issue published online: 1 JUL 2003
- Article first published online: 9 MAY 2003
- Manuscript Accepted: 21 FEB 2003
The study of measurement error, observer variation and agreement between different methods of measurement are frequent topics in the imaging literature. We describe the problems of some applications of correlation and regression methods to these studies, using recent examples from this literature. We use a simulated example to show how these problems and misinterpretations arise. We describe the 95% limits of agreement approach and a similar, appropriate, regression technique. We discuss the difference vs. mean plot, and the pitfalls of plotting difference against one variable only. We stress that these are questions of estimation, not significance tests, and show how confidence intervals can be found for these estimates. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.