Bland-Altman Analysis and Trending Assessment • BAtrending

A package for conveniently conducting a Bland-Altman including assessment of trending ability.

Installation

You can install BAtrending from GitHub with:

# install.packages("pak")
pak::pak("JohannesNE/BAtrending")

devtools::install_github("JohannesNE/BAtrending")

Example

BAtrending package includes a small sample dataset, CO. It contains paired measurements of cardiac output (CO) with two methods: radionuclide ventriculography (rv) and impedance cardiography (ic). The dataset was published in Bland JM, Altman DG. (1999) Measuring agreement in method comparison studies. Statistical Methods in Medical Research 8, 135-160.

The CO dataset has 60 measurements in 12 subjects.

library(BAtrending)

BA_CO <- compare_methods(CO, ref_col = "rv", alt_col = "ic", id_col = "sub")
# Bootstrap confidence intervals
BA_CO <- add_confint(BA_CO)

BA_plot_combine(BA_CO, aspect_ratio = 1)

The object (BA_CO) returned by compare_methods() contains a number of parameters from both the standard Bland-Altman analysis and for assessing trending ability. The print() method gives an overview:

BA_CO
#> 60 paired measurements in 12 subjects
#> 
#>                                    est      [95% CI] 
#> === Distribution ===
#> Mean                           :   5.035 [ 4.362;  5.748] 
#> Between-subject variation (SD) :   1.210 [ 0.712;  1.703] 
#> Within-subject variation (SD)  :   0.283 [ 0.225;  0.340] 
#> Total variation (SD)           :   1.243 [ 0.767;  1.726] 
#> 
#> === Method comparison ===
#> Bias (alt - ref)               :  -0.705 [-1.251; -0.207] 
#> Between-subject variation (SD) :   0.934 [ 0.541;  1.305] 
#> Within-subject variation (SD)  :   0.413 [ 0.332;  0.497] 
#> Total variation (SD)           :   1.022 [ 0.674;  1.369] 
#> Intraclass correlation
#> └ Between/Total variance       :   0.836 [ 0.625;  0.919] 
#> Limits of agreement (95%)
#> ├ Upper limit                  :   1.298 [ 0.398;  2.094] 
#> └ Lower limit                  :  -2.707 [-3.567; -1.816] 
#> Percentage error               :   0.398 [ 0.263;  0.534] 
#> 
#> --- Trending ---
#> Within-subject perc. error     :   0.161 [ 0.129;  0.194] 
#> Change LoA [±] (95%)           :   1.146 [ 0.919;  1.378]

Citation

citation("BAtrending")

To cite package ‘BAtrending’ in publications use:

YourLastName Y, CoauthorLastName C (2023). “BATrending paper.” Journal of Important Research, 10(2), 123-456. doi:10.xxxx/your.paper.doi.here https://doi.org/10.xxxx/your.paper.doi.here.

A BibTeX entry for LaTeX users is

@Article{, title = {BATrending paper}, author = {YourFirstName YourLastName and CoauthorFirstName CoauthorLastName}, journal = {Journal of Important Research}, year = {2023}, volume = {10}, number = {2}, pages = {123–456}, doi = {10.xxxx/your.paper.doi.here}, }

Please also cite the ‘lme4’ package, upon which ‘BAtrending’ relies heavily. See citation("lme4").