Agreement between methods of measurement with multiple observations per individual.
Limits of agreement provide a straightforward and intuitive approach to agreement between different methods for measuring the same quantity. When pairs of observations using the two methods are independent, i.e., on different subjects, the calculations are very simple and straightforward. Some authors collect repeated data, either as repeated pairs of measurements on the same subject, whose true value of the measured quantity may be changing, or more than one measurement by one or both methods of an unchanging underlying quantity. In this paper we describe methods for analysing such clustered observations, both when the underlying quantity is assumed to be changing and when it is not.
Bland
J Martin
JM
Department of Health Sciences, University of York, York, UK. mb55@york.ac.uk
Altman
Douglas G
DG
D000465:Algorithms; D000704:Analysis of Variance; D001699:Biometry / Q000379:methods*; D002307:Cardiography, Impedance / Q000706:statistics & numerical data; D019411:Clinical Laboratory Techniques / Q000706:statistics & numerical data*; D019937:Diagnostic Techniques and Procedures / Q000706:statistics & numerical data*; D006801:Humans; D015635:Radionuclide Ventriculography / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D013318:Stroke Volume / Q000502:physiology