The webtool can generate several visualizations of paired data to enable the quantitative comparison of their differences, known as the Bland-Altman plot. The specifics of Bland-Altman plots for comparing methods have been detailed in a paper by Bland and Altman (1986). More advanced uses of these plots have been detailed in a follow-up paper by Bland and Altman (1999). Users are advised to familiarize themselves with the methods prior to generating plots. Background information about the app can be found in the publication "BA-plotteR – A web tool for generating Bland-Altman plots and constructing limits of agreement", Goedhart and Rishniw (2021).
This provides a table of the relevant values and can be downloaded or copied.
The Shapiro Wilk Test tests for the normality of the differences. A P<0.05 indicates that the differences are NOT normally distributed and an alternative option for comparing methods (e.g. a normalization or non-parametric method) should be considered.
This value should only be reported if the user is comparing pairs of measurements by the same method (to examine within-method variability or agreement). The coefficient of reproducibility is not applicable if two methods are being compared.
The plot can be saved as a PNG file or a PDF file. The PDF can be opened and edited with Adobe Illustrator to allow for fine adjustments of the lay-out.The data from the summary table can be copied or downloaded as a file.
The webtool is created and maintained by Joachim Goedhart in collaboration with Mark Rishniw Bug reports and feature requests can be communicated in several ways:
Source code is available at github/JoachimGoedhart Please cite our publication if you use the app: "BA-plotteR – A web tool for generating Bland-Altman plots and constructing limits of agreement" - doi: 10.1016/j.rvsc.2021.05.017
Find our other dataViz apps at https://huygens.science.uva.nl