Variable Life Adjusted Display and Other Risk-Adjusted Quality Control Charts

Contains functions to set up risk-adjusted quality control charts in health care. For the variable life adjusted display (VLAD) proposed by Lovegrove et al. (1997) signaling rules derived in Wittenberg et al. (2018) are implemented. Additionally, for the risk-adjusted cumulative sum chart based on log-likelihood ratio statistic introduced by Steiner et al. (2000) average run length and control limits can be computed with fast and accurate Markov chain approximations developed in Knoth et al. (2019) .

vlad

An R-package which contains functions to set up risk-adjusted quality control charts in health care.

Main features

Risk-adjusted CUSUM chart control limit calculations based on fast and accurate Markov chain approximations (Knoth, Wittenberg, and Gan 2019)
Risk-adjusted CUSUM chart based on E-O (Wittenberg, Gan, and Knoth 2018)
Risk-adjusted CUSUM chart based on log-likelihood ratio statistic (Steiner et al. 2000)
Algorithms are implemented using Rcpp, RcppArmadillo and parallel computation

Installation

You can install the released version of vlad from CRAN with:

install.packages("vlad")

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("wittenberg/vlad")

The package compiles C++ source code during installation, therefore you need the appropriate compilers:

On Windows you need Rtools available from CRAN.

On macOS you need the Clang 6.x compiler and the GNU Fortran compiler from macOS tools. Having installed the compilers, you need to open a terminal and start R via ‘PATH=/usr/local/clang6/bin:$PATH R’. You can then install the package via devtools::install_github(“wittenberg/vlad”)

Examples

Supplemental material: Risk-adjusted CUSUM charts under model error

Authors

Philipp Wittenberg and Sven Knoth

License

GPL (>= 2)

References

Knoth, S, P Wittenberg, and FF Gan. 2019. “Risk-Adjusted CUSUM Charts Under Model Error.” Statistics in Medicine 38 (12): 2206–18. https://doi.org/10.1002/sim.8104.

Steiner, SH, RJ Cook, VT Farewell, and T Treasure. 2000. “Monitoring Surgical Performance Using Risk-Adjusted Cumulative Sum Charts.” Biostatistics 1 (4): 441–52. https://doi.org/10.1093/biostatistics/1.4.441.

Wittenberg, P, FF Gan, and S Knoth. 2018. “A Simple Signaling Rule for Variable Life-Adjusted Display Derived from an Equivalent Risk-Adjusted CUSUM Chart.” Statistics in Medicine 37 (16): 2455–73. https://doi.org/10.1002/sim.7647.