Modelled population HIV impact of an AI health companion (Aimee) on HIV testing and PrEP uptake among South African AGYW, using EpiModelHIV (SSA heterosexual module).
# epimodelhiv-aimee-agyw
**Modelled population HIV impact of an AI health companion (Aimee) on testing and PrEP uptake among South African AGYW.**
A network-based HIV transmission modelling study using
EpiModelHIV (SSA heterosexual module)
to estimate the population-level HIV-incidence impact of an AI chatbot that
increases HIV-testing frequency and PrEP uptake among adolescent girls and
young women (AGYW, 15–24) in South Africa.
> **Status:** scoping / scaffold. Not yet calibrated. No results are valid yet.
---
## The idea in one diagram
```
Clover Field Study (observational) → chatbot effect on testing & PrEP uptake
│ │
│ ▼
│ EpiModelHIV (SSA heterosexual, AGYW)
│ │
▼ ▼
effect-size inputs ───────────────► counterfactual scenarios
│
▼
HIV infections averted by the chatbot
```
The empirical cohort study estimates **who engages → who tests / starts PrEP**.
This model propagates those behavioural changes to **population HIV incidence**.
## Key design decisions
- **Population:** AGYW 15–24, heterosexual, generalized epidemic (NOT MSM).
Age-disparate partnerships (AGYW ↔ older male partners) are retained — they are
the dominant incidence driver.
- **The chatbot is not modelled mechanistically.** Its *effect* is applied as a
perturbation to existing model parameters: HIV-testing rate, PrEP
initiation/coverage, and (if supported by data) PrEP persistence.
- **Associational → causal discipline.** Cohort effects are confounded by
self-selection, so they enter as a **scenario range** (conservative / central /
optimistic), never a single causal point estimate.
## Model foundation
The study builds on the **EpiModel Gallery "HIV Transmission with Care Cascade
and PrEP"** model (MIT licensed, runs on current **EpiModel 2.6.x**) — vendored
in `R/base_model/`. It already provid …