DMHEE_THR

This repo is a redevelopment of the Total Hip Replacement (THR) model from the DMHEE textbook ¹ using computing strategies for reproducibility. The original THR model was developed by Briggs et al.², to assess the cost-effectiveness of two or three alternative surgical prostheses.

The re-development involved organizing the relevant methodological sequence into an automated workflow. To capture the provenance of the results, the workflow was designed to incorporate the procedures of the economic evaluation as well as those used to estimate the parameter inputs.

This effort was initiated in response to the fact that the original textbook exercises are designed and organized for a spreadsheet environment. Adapting this project to a programming language (R) offered the ability to show how this model could be developed in a reproducible fashion. A collection of previously identified strategies for reproducibility were used to achieve a level of reproducibility that would allow for the reliable re-generation of results, including intermediate data sets.

Documentation

• Progress
• Summary of the THR Model

Project Organization

This project is organized using a consistent directory structure which could be applied to most projects. Additionally, it allows for the use of relative file paths within scripts - which is essential for portability. An outline of the directory structure is presented below.

PROJECT-DIRECTORY
|-data\
|   |-data-raw\
|   |-data-gen\
|     |-Model-Params\
|     |-Simulation-Output\
|-docs\
|-results\
|-src\
|   |-FUNS\
|   |-01_Simulations
|   |-02_Analysis

data : The data directory is used to store both raw (data-raw) and generated (data-gen) data set. In the latter category, additional sub-directories are used to distinguish between Model Parameters and Simulation Output.

docs : The docs directory is used to store documents relevant to the project. This may include project-specific documentation, diagrams, or even manuscripts and reports.

results : The results directory is used to store results from the project. In this case a result is conceptualized as output which is ready to be placed in a manuscript or report. This may include a formatted display table or different kinds of plots produced for the project.

src : The src is used to store all of the scripts for a project. It is organized into three specific sub-directories. The first sub-directory, FUNS, is used to store functions which are specific to the project in general. This is where all of the functions used to define the decision model and prepare its parameter inputs are stored. The second sub-directory, 01_Simulations, is used to store scripts which execute all relevant simulations for this project. The third sub-directory, 02_Analysis, is used to store scripts which perform the relevant steps to produce a specific result. In other words, these scripts accept simulation output as input and return a result (i.e. tabular or graphical) which will be stored in the results directory.

Notes

• ℹ️ Add Function to return Display Table for
  Cost-Effectiveness Results.
  • There is a considerable amount of code duplication.
  • Requirements:
    • Deterministic vs probabilistic output.
    • Scenarios as row groups.

Footnotes

1. Briggs AH, Claxton K, Sculpher MJ. Decision modelling for health economic evaluation. Oxford: Oxford University Press; 2006. 237 p. (Briggs A, Gray A, editors. Oxford handbooks in health economic evaluation). ↩

2. Briggs A, Sculpher M, Dawson J, Fitzpatrick R, Murray D, Malchau H. Modelling the cost-effectiveness of primary hip replacement: how cost-effective is the Spectron compared to the Charnley prosthesis? 2003 Dec;52. ↩