Associations Beyond Chance (ABC)

The ABC model provides a Bayesian framework to infer multimorbidity associations between health conditions from Electronic Health Records. The outputs are posterior distribution over pairwise association values, which can be assembled and visualised as multimorbidity weigthed network.

The ABC model was presented on the article "Multimorbidity analysis with low condition counts: a robust Bayesian approach for small but important subgroups". This repository also provides code to reproduce the experiments and visualisations there. If you use this code, please cite the paper:

Romero Moreno G., Restocchi V., Fleuriot JD., Anand A., Mercer SW., Guthrie B. (2024). Multimorbidity analysis with low condition counts: a robust Bayesian approach for small but important subgroups; eBioMedicine, Volume 102, 105081, ISSN 2352-3964, https://doi.org/10.1016/j.ebiom.2024.105081.

@article{ROMEROMORENO2024105081,
title = {Multimorbidity analysis with low condition counts: a robust Bayesian approach for small but important subgroups},
journal = {eBioMedicine},
volume = {102},
pages = {105081},
year = {2024},
issn = {2352-3964},
doi = {https://doi.org/10.1016/j.ebiom.2024.105081},
url = {https://www.sciencedirect.com/science/article/pii/S2352396424001166},
author = {Guillermo {Romero Moreno} and Valerio Restocchi and Jacques D. Fleuriot and Atul Anand and Stewart W. Mercer and Bruce Guthrie},
}

Installation and dependencies

You can install the package using pip or conda.Be aware that the package and all its dependencies may take a few GB of space.

While the code is in python, Bayesian inference is performed via Stan through the python API cmdstanpy (version 1.1.0). However, the model (defined in the file ABC/models/MLTC_atomic_hyp_mult.stan) could also work with any other stan interface.

Installation with pip (for running the method from the command line)

For installing the PyPI package with pip, you just will just need to:

1. Run python -m pip install abc_network on the terminal to install the package
2. Run install_cmdstan (Linux/MacOSX) or install_cmdstan --compiler (Windows) on the terminal to install Stan, the Bayesian inference library. For more info check their documentation.

Installation with conda (for running jupyter notebooks or reproducing results)

• Install Anaconda (if not already installed)
• Download the code of the GitHub repository
• At the root folder of the repository, execute conda env create -n ABC --file packages.yml¹ for creating an environment called ABC with all the required packages
• Activate the environment with conda activate ABC. You can then run the python scripts directly or set up a jupyter notebook server (by running jupyter notebook)

Using the model

You can use our model either directly from the command line --- without the need of diving into python code --- or integrate it into your python scripts.

Command line

If you installed the package through PyPI, our model can be used simply by running ABC "path/to/dataset_file.csv", which will fit the model and generate an output folder output at the folder where the command is run, including the saved fitted model and files with the results. For more information on additional arguments that this command can take, just execute ABC --help.

Note that the csv file containing your dataset must:

• be in long format (i.e. patients as rows and conditions as columns),
• only have the columns of interest, which must only have BINARY VALUES, and
• have the first row with the name of the columns and the first column with the row index

If you installed the package through conda, once you have activated the conda environment you can run python3 ABC/model.py --data_path "path/to/dataset_file.csv" for exactly the same functionality.

Integration to python scripts

You can also integrate our model into other python code directly. You can see an example snippet on how to do so below.

from ABC.model import ABCModel
from ucimlrepo import fetch_ucirepo 

# This loads an example dataset. Swap these lines for those loading your dataset
dataset = fetch_ucirepo(name='CDC Diabetes Health Indicators')
data = pd.concat([dataset.data.features, dataset.data.targets ], axis=1)
bin_vars = dataset.variables[dataset.variables["type"] == "Binary"]["name"].to_list()
# Make sure to use columns with binary variables only

model = ABCModel()
model.load_fit(data, "choose_name_for_model", column_names=bin_vars, num_warmup=500, num_samples=2000, random_seed=1)

ABC = model.get_associations()  # This retrieves the whole distribution for all association pairs
results = model.get_results_dataframe(credible_inteval_pvalue=0.01)  # This creates a table with summary statistics

A more detailed example with step-by-step intructions on how to use the model and produce outputs and visualisations within python code can be found at the tutorial notebook 'ABC_to_ABC.ipynb'.

Reproducing results

You can replicate the results and figures from the "Multimorbidity analysis with low condition counts: a robust Bayesian approach for small but important subgroups" article by running the notebook notebooks/results.ipynb. However, note that this will only be possible if you have access to the dataset used in the study.

You can still reproduce the results shown in that notebook on a different dataset, for which you will need to adapt all functions and variables within the file ABC/data.py to your dataset characteristics and then rerun notebooks/results.ipynb --- or use the functions in the file ABC/results.py.

Repository structure

• ABC/: python files with the basic classes and functions.
• ABC/models/: files defining Stan models.
• ABC/output/: folder in which to save the fitted models.
• notebooks/: results and examples implementing our models and code.
• figs/: folder in which to save the figures produced in the notebooks.

Acknowledgements

Functions and notebooks were inspired by this repository.

The logo has been designed by Paola Galdi (@paola-g).

Contact

The code has not been extensively tested in other platforms, so if you encounter any error, submit an Issue on GitHub or my email Guillermo.RomeroMoreno@ed.ac.uk. Feel free to raise an Issue or contact me likewise if you any question, comment, or feedback; these will be highly appreciated.

Footnotes

1. Or directly execute conda create -n ABC -c conda-forge numpy=1.22.3 scipy=1.8.0 pandas=1.4.2 matplotlib=3.5.1 seaborn=0.13.1 networkx=2.8 bokeh=3.3.0 cmdstanpy=1.1.0 jupyter. ↩