Skip to main content
Mail a PDF copy of this page to:
(Your email address will not be added to a mailing list)
Show menu

Method comparison: Comparison of multiple methods

Next selectMethod comparison & evaluation
Next selectComparison of multiple methods


Comparison of multiple methods is an extension of the Bland-Altman plot (Bland & Altman, 1986 and 1999) for more than two methods. For each method, the differences with a reference method are plotted against the values of this reference method (Krouwer, 2008).

The procedure produces multiple bias plots in one single display with all axes aligned to facilitate comparison of the different methods.

If duplicate or multiple measurements (with two methods) were performed per subject, you should use Bland-Altman plot with multiple measurements per subject.

Required input

Dialog box for multiple method comparison

Select the variables for the methods you want to compare.


(*) or ratios when this option was selected.


The results panel displays the following information:

Results for multiple method comparison


The graphical display consists of multiple frames with Bland & Altman plots using the selected options.

Multiple method comparison graph (Bland-Altman plots)

Unlike other MedCalc graphs, this graphical display has limited editing possibilities:

Confidence intervals

Optionally, confidence intervals may be displayed for the average difference and for the limits of agreement. These confidence intervals can be represented as error bars or horizontal lines. Right-click on the error bar to set formatting options.


See also