Evaluating Mental Health Integration in PrEP Programs to Reduce HIV Incidence Among US Gay and Bisexual Men

This repository holds the code for our network modeling study of mental health integration in PrEP programs.

Paper and engine

Onwubiko UN, Le Guillou A, Chamberlain AT, Benkeser D, Holland DP, Baral SD, Jenness SM. Evaluating mental health integration in PrEP programs to reduce HIV incidence among US gay and bisexual men: a network modeling study. BMC Health Serv Res. 2026; 26: 1381. doi:10.1186/s12913-026-15074-0

The EpiModelHIV engine for this paper is release MentalHealth-BMCHSR of EpiModel/EpiModelHIV. Install it with:

remotes::install_github("EpiModel/EpiModelHIV@MentalHealth-BMCHSR")

The setup script (R/00-setup.R) installs EpiModelHIV-p, which is private. Use the install line above instead.

ARTnetData is a private package. It is needed only to re-estimate the networks. The paper's networks were estimated with ARTnet 2.7.0, which is no longer public, so renv.lock installs ARTnet 2.9.3, the first version in the public ARTnet repository. Networks re-estimated with it may not match the paper's exactly.

The rest of this README is the EpiModelHIV-Template guide this project was built from.

EpiModeHIV-Template

Introduction

This template is a scaffold for an EpiModeHIV applied project. Before reading on make sure you have read the getting started wiki page and done all the relevant steps.

From now on, we refer to the applied project as applied_proj and to your custom EpiModeHIV-p branch as EpiModeHIV-p@applied_proj.

At this point, we assume that you have your applied project cloned on your local computer and your EpiModeHIV-p branch checked out as well.

This template is divided into several steps. They are separated as sub-directories under the R/ folder. They each contain a README.md file. We will describe each of them below.

Conventions

Each script in this project is structured in the same way to simplify reading. As these applied project are pretty complex, you are advised to read the code and make sure you understand what it does before running it. Comments are often present to guide you along the way.

Top level scripts

By top level scripts we mean the scripts that will be executed directly by the user.

They are all the scripts starting with as number (e.g. 1-estimation.R) or the scripts starting with workflow (e.g. workflow-networks.R).

These scripts are meant to be run in clean R session. It is advised to restart R before running these scripts. This can be done by pressing Ctrl+Shift+F10 on RStudio. (Note, .rs.restartR() is NOT the same at all).

All other scripts are utilities. They provide variables or functions to the top level ones and should not be run on their own.

The z-context.R scripts

Each step contains a z-context.R. It defines specific parameters differently depending on the context of executions.

The two possible contexts are local or hpc. Local means your own computer and hpc is the High Performance Computing cluster where you will run your large scale simulations.

You will probably not need to edit these files.

Simply know that the context switching is done by setting the following variable before these scripts are sourced:

hpc_context <- TRUE

General advise on making new scripts

When creating a new top level script you should adhere to the global structure used all over this repo. These project of ours are very complex with many moving pieces. Trying to keep them as clean as possible helps a lot in not getting lost.

Getting started: fitting your project

First of, some scripts will need a few modification to fit your project.

shared_variables.R

This files contains the generic configuration for the project. It will be sourced by every top level scripts.

Open it now and modify the following variables to fit your project:

EMHIVp_branch <- "applied_proj"             # the name of your project
EMHIVp_dir <- "Desktop\\git\\EpiModelHIV-p" #  path to EpiModeHIV-p  directory

time_unit <- 7     # number of days in a time step (7 for weekly)

hpc_configs.R

This scripts contains configuration for running things on the HPC.

Open it now and modify the mail_user variable to reflect your own e-mail address. It will be used to notify you of the progress of your jobs on the HPC.

The current_git_branch variable should be left to main most of the time. Modify it only if you created an new branch and want to run code from it on the HPC.

If you are working with the RSPH HPC, leave the rest unchanged. Otherwise modify the code accordingly.

netsim_settings.R

This script defines the default settings for netsim. The default values are probably correct. Modify the init variable to be init <- init_msm() if you need to disable the STIs in your model.

z-test.R

This file is for you to test code without making another script dirty. As a reminder, you should always write code in a file and not in the R console. Even if it's just for a quick test.

Getting started: setting up the environment

Go to the 00-setup.R file.

Run the renv::init(bare = TRUE) line and restart the R session before carrying on.

Run the rest of the script. It will install all the necessary packages.

At this point you can go the README.md file for step A-networks

Table of content

Below is a list of all the steps with a quick description.

• A-networks: Estimate and diagnosed the network models.
• B-netsim_explore: Get familiar with running network models with netsim
• C-netsim_scenarios: Run network models with the scenario API
• D-restart_point: Mandatory non interactive step
• E-intervention_explore: Get familiar with restarting network models with netsim
• F-intervention_scenarios: Run intervention scenarios and process results for publication
• Z-calibration: advanced step addressing calibration

Common mistakes

Here is a list of commonly made mistakes to help you avoid them as you go:

Workflow directories

As you start working with the HPC, you will create workflow directories. Do not forget to delete them locally AND on the HPC before making a new one with the same name.

On the HPC this can be done with:

rm -rf workflows/<the name of your workflow>