Webpage for Bland-Altman analysis

This page shows how to conduct a Bland-Altman analysis, using a set of simulated data that have been prepared for demonstration purposes.

The steps of this analysis are (details follow below):

The format of the data

The data are laid out in three columns: the first value in each row identifies the individual, and the second two values are measurements made in that individual, at the same time, with two different methods (for example, these could be measurements of cardiac output, using two different instruments).

The example data

The example data consist of data from 20 individuals. In each individual, 15 measurements have been made by two different methods, given in the second and third columns. This gives 300 rows of data. To obtain the simulated data, click here.

You can copy these data from the browser to your clipboard (use control-A to select, and then control-C to copy). Then return to the original page, and click on the link Bland-Altman Analysis to go to the analysis page.

The analysis page

On the analysis page, you will find a box with the words "paste the data here". Click in the box and use control-V to paste the clipboard contents. Then click on the button "Perform Bland-Altman analysis".

When the analysis is done, a table of the input data is given at the bottom of the page. This allows a check that the data have been correctly entered.

A guide on the interpretation of the results is here.

To allow further explanation of the effects of different methods of analysis, a comparison of results obtained by using different methods can be obtained here. Note that these different methods may well NOT be the appropriate way to analyse the data. (Clearly, if the analysis is inappropriate, such results should NOT be reported).

Supported browsers

At present, the code for this analysis has only been tested with the Firefox and the Chrome browsers. Internet Explorer will probably not work. JavaScript should be enabled.


The greatest possible care was taken in compiling the content of this website and providing correct analysis results. It can happen, though, that the provided information is incomplete or inaccurate. No rights may be derived from the content of this website. The LUMC accepts no liability for direct or indirect damages resulting from the content of the website and/or the analysis results.

If the website contains links to third parties, the LUMC is similarly not liable for direct or indirect damages resulting from the information or services provided by those third parties.

The content of this website is subject to copyright. No part of the content, except for the analysis results, may be used in any form and/or in any way whatsoever without prior written consent. Consent may be requested from the Department of Anesthesiology of the LUMC.


Send comments to Erik Olofsen.